# Evolution of Ethereum

## The history of Ethereum <a href="#the-history-of-ethereum" id="the-history-of-ethereum"></a>

A timeline of all the major milestones, forks, and updates to the Ethereum blockchain.

#### What are forks?

Forks are changes to the rules of the Ethereum protocol which often include planned technical upgrades.

Looking for future protocol upgrades? [Learn about upcoming upgrades to Ethereum](https://ethereum.org/en/upgrades/).

### 2022 <a href="#id-2022" id="id-2022"></a>

#### Gray Glacier <a href="#gray-glacier" id="gray-glacier"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg)`Jun-30-2022 10:54:04 AM +UTC`\
🧱Block number: [15,050,000](https://etherscan.io/block/15050000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg)ETH price: $1,069 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20220630094629/https://ethereum.org/en/)

**Summary**

The Gray Glacier network upgrade pushed back the [difficulty bomb](https://ethereum.org/en/glossary/#difficulty-bomb) by three months. This is the only change introduced in this upgrade, and is similar in nature to the [Arrow Glacier](https://ethereum.org/en/history/#arrow-glacier) and [Muir Glacier](https://ethereum.org/en/history/#muir-glacier) upgrades. Similar changes have been performed on the [Byzantium](https://ethereum.org/en/history/#byzantium), [Constantinople](https://ethereum.org/en/history/#constantinople) and [London](https://ethereum.org/en/history/#london) network upgrades.

* [EF Blog - Gray Glacier Upgrade Announcement](https://blog.ethereum.org/2022/06/16/gray-glacier-announcement/)

### 2021 <a href="#id-2021" id="id-2021"></a>

#### Arrow Glacier <a href="#arrow-glacier" id="arrow-glacier"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg)`Dec-09-2021 07:55:23 PM +UTC`\
🧱Block number: [13,773,000](https://etherscan.io/block/13773000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg)ETH price: $4,111 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20211207064430/https://ethereum.org/en/)

**Summary**

The Arrow Glacier network upgrade pushed back the [difficulty bomb](https://ethereum.org/en/glossary/#difficulty-bomb) by several months. This is the only change introduced in this upgrade, and is similar in nature to the [Muir Glacier](https://ethereum.org/en/history/#muir-glacier) upgrade. Similar changes have been performed on the [Byzantium](https://ethereum.org/en/history/#byzantium), [Constantinople](https://ethereum.org/en/history/#constantinople) and [London](https://ethereum.org/en/history/#london) network upgrades.

* [EF Blog - Arrow Glacier Upgrade Announcement](https://blog.ethereum.org/2021/11/10/arrow-glacier-announcement/)
* [Ethereum Cat Herders - Ethereum Arrow Glacier Upgrade](https://medium.com/ethereum-cat-herders/ethereum-arrow-glacier-upgrade-e8d20fa4c002)

#### Altair <a href="#altair" id="altair"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg)`Oct-27-2021 10:56:23 AM +UTC`\
🧱Epoch number: 74,240\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg)ETH price: $4,024 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20211026174951/https://ethereum.org/en/)

**Summary**

The Altair upgrade was the first scheduled upgrade for the [Beacon Chain](https://ethereum.org/en/upgrades/beacon-chain). It added support for 'sync committees' — enabling light clients as well as bringing validator inactivity and slashing penalties up to their full values.

* [Read the Altair upgrade specification](https://github.com/ethereum/consensus-specs/tree/dev/specs/altair)

![🎉](https://twemoji.maxcdn.com/2/svg/1f389.svg)**Fun fact!**

Altair was the first major network upgrade that had an exact rollout time. Every upgrade prior had been based on a declared block number on the proof-of-work chain, where block times vary. The Beacon Chain does not require solving for Proof of Work, and instead works on a time-based epoch system consisting of 32 twelve-second "slots" of time where validators can propose blocks. This is why we knew exactly when we would hit epoch 74,240 and Altair went live!

* [Beaconcha.in Glossary - Slots](https://kb.beaconcha.in/glossary#slots)

#### London <a href="#london" id="london"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Aug-05-2021 12:33:42 PM +UTC`\
🧱 Block number: [12,965,000](https://etherscan.io/block/12965000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $2,621 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20210805124609/https://ethereum.org/en/)

**Summary**

The London upgrade introduced [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559), which reformed the transaction fee market, along with changes to how gas refunds are handled and the [Ice Age](https://ethereum.org/en/glossary/#ice-age) schedule.

* [Are you a dApp developer? Be sure to upgrade your libraries and tooling.](https://github.com/ethereum/execution-specs/blob/master/network-upgrades/london-ecosystem-readiness.md)
* [Read the Ethereum Foundation announcement](https://blog.ethereum.org/2021/07/15/london-mainnet-announcement/)
* [Read the Ethereum Cat Herder's explainer](https://medium.com/ethereum-cat-herders/london-upgrade-overview-8eccb0041b41)

#### Berlin <a href="#berlin" id="berlin"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Apr-15-2021 10:07:03 AM +UTC`\
🧱 Block number: [12,244,000](https://etherscan.io/block/12244000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $2,454 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20210415093618/https://ethereum.org/)

**Summary**

The Berlin upgrade optimized gas cost for certain EVM actions and increases support for multiple transaction types.

* [Read the Ethereum Foundation announcement](https://blog.ethereum.org/2021/03/08/ethereum-berlin-upgrade-announcement/)
* [Read the Ethereum Cat Herder's explainer](https://medium.com/ethereum-cat-herders/the-berlin-upgrade-overview-2f7ad710eb80)

### 2020 <a href="#id-2020" id="id-2020"></a>

#### Beacon Chain genesis <a href="#beacon-chain-genesis" id="beacon-chain-genesis"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Dec-01-2020 12:00:35 PM +UTC`\
🧱 Beacon Chain block number: [1](https://beaconscan.com/slot/1)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $586.23 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20201207184633/https://www.ethereum.org/en/)

**Summary**

The [Beacon Chain](https://ethereum.org/en/upgrades/beacon-chain/) needed 16384 deposits of 32 staked ETH to ship securely. This happened on November 27, meaning the Beacon Chain started producing blocks on December 1, 2020. This is an important first step in achieving the [Ethereum vision](https://ethereum.org/en/upgrades/vision/).

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2020/11/27/eth2-quick-update-no-21/)

[![📃](https://twemoji.maxcdn.com/2/svg/1f4c3.svg)](https://ethereum.org/en/upgrades/beacon-chain/)

***

#### Staking deposit contract deployed <a href="#staking-deposit-contract" id="staking-deposit-contract"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Oct-14-2020 09:22:52 AM +UTC`\
🧱 Block number: [11,052,984](https://etherscan.io/block/11052984)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $379.04 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20201104235727/https://ethereum.org/en/)

**Summary**

The staking deposit contract introduced [staking](https://ethereum.org/en/glossary/#staking) to the Ethereum ecosystem. Although a [Mainnet](https://ethereum.org/en/glossary/#mainnet) contract, it had a direct impact on the timeline for launching the [Beacon Chain](https://ethereum.org/en/upgrades/beacon-chain/), an important [Ethereum upgrade](https://ethereum.org/en/upgrades/).

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2020/11/04/eth2-quick-update-no-19/)

[![📃](https://twemoji.maxcdn.com/2/svg/1f4c3.svg)](https://ethereum.org/en/staking/)

***

#### Muir Glacier <a href="#muir-glacier" id="muir-glacier"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Jan-02-2020 08:30:49 AM +UTC`\
🧱 Block number: [9,200,000](https://etherscan.io/block/9200000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $127.18 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20200103093618/https://ethereum.org/)

**Summary**

The Muir Glacier fork introduced a delay to the [difficulty bomb](https://ethereum.org/en/glossary/#difficulty-bomb). Increases in block difficulty of the [proof-of-work](https://ethereum.org/en/developers/docs/consensus-mechanisms/pow/) consensus mechanism threatened to degrade the usability of Ethereum by increasing wait times for sending transactions and using dapps.

* [Read the Ethereum Foundation announcement](https://blog.ethereum.org/2019/12/23/ethereum-muir-glacier-upgrade-announcement/)
* [Read the Ethereum Cat Herder's explainer](https://medium.com/ethereum-cat-herders/ethereum-muir-glacier-upgrade-89b8cea5a210)

### 2019 <a href="#id-2019" id="id-2019"></a>

#### Istanbul <a href="#istanbul" id="istanbul"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Dec-08-2019 12:25:09 AM +UTC`\
🧱 Block number: [9,069,000](https://etherscan.io/block/9069000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $151.06 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20191216101254if*/https://ethereum.org/)

**Summary**

The Istanbul fork:

* Optimized the [gas](https://ethereum.org/en/glossary/#gas) cost of certain actions in the [EVM](https://ethereum.org/en/developers/docs/ethereum-stack/#ethereum-virtual-machine).
* Improved denial-of-service attack resilience.
* Made [layer-2 scaling](https://ethereum.org/en/developers/docs/scaling/#layer-2-scaling) solutions based on SNARKs and STARKs more performant.
* Enabled Ethereum and Zcash to interoperate.
* Allowed contracts to introduce more creative functions.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2019/11/20/ethereum-istanbul-upgrade-announcement/)

#### Constantinople <a href="#constantinople" id="constantinople"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Feb-28-2019 07:52:04 PM +UTC`\
🧱 Block number: [7,280,000](https://etherscan.io/block/7280000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $136.29 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20190415163751/https://www.ethereum.org/)

**Summary**

The Constantinople fork:

* Ensured the blockchain didn't freeze before [proof-of-stake was implemented](https://ethereum.org/en/history/#beacon-chain-genesis).
* Optimized the [gas](https://ethereum.org/en/glossary/#gas) cost of certain actions in the [EVM](https://ethereum.org/en/developers/docs/ethereum-stack/#ethereum-virtual-machine).
* Added the ability to interact with addresses that haven't been created yet.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2019/02/22/ethereum-constantinople-st-petersburg-upgrade-announcement/)

### 2017 <a href="#id-2017" id="id-2017"></a>

#### Byzantium <a href="#byzantium" id="byzantium"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Oct-16-2017 05:22:11 AM +UTC`\
🧱 Block number: [4,370,000](https://etherscan.io/block/4370000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $334.23 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20171017201143/https://www.ethereum.org/)

**Summary**

The Byzantium fork:

* Reduced block [mining](https://ethereum.org/en/developers/docs/consensus-mechanisms/pow/mining/) rewards from 5 to 3 ETH.
* Delayed the [difficulty bomb](https://ethereum.org/en/glossary/#difficulty-bomb) by a year.
* Added ability to make non-state-changing calls to other contracts.
* Added certain cryptography methods to allow for [layer-2 scaling](https://ethereum.org/en/developers/docs/scaling/#layer-2-scaling).

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2017/10/12/byzantium-hf-announcement/)

### 2016 <a href="#id-2016" id="id-2016"></a>

#### Spurious Dragon <a href="#spurious-dragon" id="spurious-dragon"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Nov-22-2016 04:15:44 PM +UTC`\
🧱 Block number: [2,675,000](https://etherscan.io/block/2675000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $9.84 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20161127154654/https://www.ethereum.org/)

**Summary**

The Spurious Dragon fork was the second response to the denial of service (DoS) attacks on the network (September/October 2016) including:

* tuning opcode pricing to prevent future attacks on the network.
* enabling 'debloat' of the blockchain state.
* adding replay attack protection.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2016/11/18/hard-fork-no-4-spurious-dragon/)

#### Tangerine whistle <a href="#tangerine-whistle" id="tangerine-whistle"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Oct-18-2016 01:19:31 PM +UTC`\
🧱 Block number: [2,463,000](https://etherscan.io/block/2463000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $12.50 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20161030043727/https://www.ethereum.org/)

**Summary**

The Tangerine Whistle fork was the first response to the denial of service (DoS) attacks on the network (September/October 2016) including:

* addressing urgent network health issues concerning underpriced operation codes.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2016/10/18/faq-upcoming-ethereum-hard-fork/)

#### DAO fork <a href="#dao-fork" id="dao-fork"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Jul-20-2016 01:20:40 PM +UTC`\
🧱 Block number: [1,920,000](https://etherscan.io/block/1920000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $12.54 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20160803215306/https://ethereum.org/)

**Summary**

The DAO fork was in response to the [2016 DAO attack](https://www.coindesk.com/markets/2016/06/25/understanding-the-dao-attack/) where an insecure [DAO](https://ethereum.org/en/glossary/#dao) contract was drained of over 3.6 million ETH in a hack. The fork moved the funds from the faulty contract to a [new contract](https://etherscan.io/address/0xbf4ed7b27f1d666546e30d74d50d173d20bca754) with a single function: withdraw. Anyone who lost funds could withdraw 1 ETH for every 100 DAO tokens in their wallets.

This course of action was voted on by the Ethereum community. Any ETH holder was able to vote via a transaction on [a voting platform](http://v1.carbonvote.com/). The decision to fork reached over 85% of the votes.

Some miners refused to fork because the DAO incident wasn't a defect in the protocol. They went on to form [Ethereum Classic](https://ethereumclassic.org/).

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2016/07/20/hard-fork-completed/)

#### Homestead <a href="#homestead" id="homestead"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Mar-14-2016 06:49:53 PM +UTC`\
🧱 Block number: [1,150,000](https://etherscan.io/block/1150000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $12.50 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20160313203843/https://www.ethereum.org/)

**Summary**

The Homestead fork that looked to the future. It included several protocol changes and a networking change that gave Ethereum the ability to do further network upgrades.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2016/02/29/homestead-release/)

### 2015 <a href="#id-2015" id="id-2015"></a>

#### Frontier thawing <a href="#frontier-thawing" id="frontier-thawing"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Sep-07-2015 09:33:09 PM +UTC`\
🧱 Block number: [200,000](https://etherscan.io/block/200000)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: $1.24 USD\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20150912193811/https://www.ethereum.org/)

**Summary**

The frontier thawing fork lifted the 5,000 [gas](https://ethereum.org/en/glossary/#gas) limit per [block](https://ethereum.org/en/glossary/#block) and set the default gas price to 51 [gwei](https://ethereum.org/en/glossary/#gwei). This allowed for transactions –– transactions require 21,000 gas. The [difficulty bomb](https://ethereum.org/en/glossary/#difficulty-bomb) was introduced to ensure a future hard fork to [Proof of Stake](https://ethereum.org/en/glossary/#pos).

* [Read the Ethereum Foundation announcement](https://blog.ethereum.org/2015/08/04/the-thawing-frontier/)
* [Read the Ethereum Protocol Update 1](https://blog.ethereum.org/2015/08/04/ethereum-protocol-update-1/)

#### Frontier <a href="#frontier" id="frontier"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) `Jul-30-2015 03:26:13 PM +UTC`\
🧱 Block number: [0](https://etherscan.io/block/0)\
![💰](https://twemoji.maxcdn.com/2/svg/1f4b0.svg) ETH price: N/A\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20150802035735/https://www.ethereum.org/)

**Summary**

Frontier was live, but barebone implementation of the Ethereum project. It followed the successful Olympic testing phase. It was intended for technical users, specifically developers. [Blocks](https://ethereum.org/en/glossary/#block) had a [gas](https://ethereum.org/en/glossary/#gas) limit of 5,000. This "thawing" period enabled miners to start their operations and for early adopters to install their clients without having to ‘rush’.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2015/07/22/frontier-is-coming-what-to-expect-and-how-to-prepare/)

### 2014 <a href="#id-2014" id="id-2014"></a>

#### Ether sale <a href="#ether-sale" id="ether-sale"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) July 22 - September 02, 2014\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20140804235628/https://www.ethereum.org/)

Ether officially went on sale for 42 days. You could buy it with BTC.

[Read the Ethereum Foundation announcement](https://blog.ethereum.org/2014/07/22/launching-the-ether-sale/)

***

#### Yellowpaper released <a href="#yellowpaper" id="yellowpaper"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) April 01, 2014\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20140509173418/https://www.ethereum.org/)

The Yellow Paper, authored by Dr. Gavin Wood, is a technical definition of the Ethereum protocol.

[View the Yellow Paper](https://github.com/ethereum/yellowpaper)

### 2013 <a href="#id-2013" id="id-2013"></a>

#### Whitepaper released <a href="#whitepaper" id="whitepaper"></a>

![📆](https://twemoji.maxcdn.com/2/svg/1f4c6.svg) November 27, 2013\
![🖥️](https://twemoji.maxcdn.com/2/svg/1f5a5.svg) [ethereum.org on waybackmachine](https://web.archive.org/web/20140208030136/http://www.ethereum.org/)

The introductory paper was published in 2013 by Vitalik Buterin, the founder of Ethereum, before the project's launch in 2015.

[![📃](https://twemoji.maxcdn.com/2/svg/1f4c3.svg)](https://ethereum.org/en/whitepaper/)