Evolution of Ethereum
ethreum.org
A timeline of all the major milestones, forks, and updates to the Ethereum blockchain.
Forks are changes to the rules of the Ethereum protocol which often include planned technical upgrades.

ETH price: $1,069 USD
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Jun-30-2022 10:54:04 AM +UTC
🧱Block number: 15,050,000
Summary
The Gray Glacier network upgrade pushed back the difficulty bomb by three months. This is the only change introduced in this upgrade, and is similar in nature to the Arrow Glacier and Muir Glacier upgrades. Similar changes have been performed on the Byzantium, Constantinople and London network upgrades.

ETH price: $4,111 USD
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Dec-09-2021 07:55:23 PM +UTC
🧱Block number: 13,773,000
Summary
The Arrow Glacier network upgrade pushed back the difficulty bomb by several months. This is the only change introduced in this upgrade, and is similar in nature to the Muir Glacier upgrade. Similar changes have been performed on the Byzantium, Constantinople and London network upgrades.

ETH price: $4,024 USD
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Oct-27-2021 10:56:23 AM +UTC
🧱Epoch number: 74,240
Summary
The Altair upgrade was the first scheduled upgrade for the 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.
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!
ETH price: $2,621 USD
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Aug-05-2021 12:33:42 PM +UTC
🧱 Block number: 12,965,000
Summary
ETH price: $2,454 USD
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Apr-15-2021 10:07:03 AM +UTC
🧱 Block number: 12,244,000
Summary
The Berlin upgrade optimized gas cost for certain EVM actions and increases support for multiple transaction types.
ETH price: $586.23 USD
ethereum.org on waybackmachine
Dec-01-2020 12:00:35 PM +UTC
🧱 Beacon Chain block number: 1
Summary
The 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.
ETH price: $379.04 USD
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Oct-14-2020 09:22:52 AM +UTC
🧱 Block number: 11,052,984
Summary
The staking deposit contract introduced staking to the Ethereum ecosystem. Although a Mainnet contract, it had a direct impact on the timeline for launching the Beacon Chain, an important Ethereum upgrade.
ETH price: $127.18 USD
ethereum.org on waybackmachine
Jan-02-2020 08:30:49 AM +UTC
🧱 Block number: 9,200,000
Summary
The Muir Glacier fork introduced a delay to the difficulty bomb. Increases in block difficulty of the proof-of-work consensus mechanism threatened to degrade the usability of Ethereum by increasing wait times for sending transactions and using dapps.
ETH price: $151.06 USD
ethereum.org on waybackmachine
Dec-08-2019 12:25:09 AM +UTC
🧱 Block number: 9,069,000
Summary
The Istanbul fork:
- Improved denial-of-service attack resilience.
- Enabled Ethereum and Zcash to interoperate.
- Allowed contracts to introduce more creative functions.
ETH price: $136.29 USD
ethereum.org on waybackmachine
Feb-28-2019 07:52:04 PM +UTC
🧱 Block number: 7,280,000
Summary
The Constantinople fork:
- Added the ability to interact with addresses that haven't been created yet.
ETH price: $334.23 USD
ethereum.org on waybackmachine
Oct-16-2017 05:22:11 AM +UTC
🧱 Block number: 4,370,000
Summary
The Byzantium fork:
- Added ability to make non-state-changing calls to other contracts.
ETH price: $9.84 USD
ethereum.org on waybackmachine
Nov-22-2016 04:15:44 PM +UTC
🧱 Block number: 2,675,000
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.
ETH price: $12.50 USD
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Oct-18-2016 01:19:31 PM +UTC
🧱 Block number: 2,463,000
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.
ETH price: $12.54 USD
ethereum.org on waybackmachine
Jul-20-2016 01:20:40 PM +UTC
🧱 Block number: 1,920,000
Summary
The DAO fork was in response to the 2016 DAO attack where an insecure 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 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. 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.
ETH price: $12.50 USD
ethereum.org on waybackmachine
Mar-14-2016 06:49:53 PM +UTC
🧱 Block number: 1,150,000
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.
ETH price: $1.24 USD
ethereum.org on waybackmachine
Sep-07-2015 09:33:09 PM +UTC
🧱 Block number: 200,000
Summary
The frontier thawing fork lifted the 5,000 gas limit per block and set the default gas price to 51 gwei. This allowed for transactions –– transactions require 21,000 gas. The difficulty bomb was introduced to ensure a future hard fork to Proof of Stake.
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 had a 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’.
Ether officially went on sale for 42 days. You could buy it with BTC.
The Yellow Paper, authored by Dr. Gavin Wood, is a technical definition of the Ethereum protocol.
The introductory paper was published in 2013 by Vitalik Buterin, the founder of Ethereum, before the project's launch in 2015.