The Ethereum Merge is Complete
The Ethereum Mainnet and Beacon chain merged at a 'Total Terminal Difficulty; (TTD) value of 58.75 Hextillion, signalling the end of Proof-of-Work (POW) and the transition to Proof-of-Stake (POS) Under Proof-of-Stake Ethereum's energy consumption is expected to be reduced by ~99.95%.
The Gray Glacier network upgrade pushed back the difficulty bomb by three months. This is the only change introduced in this upgrade.
The Arrow Glacier network upgrade pushed back the difficulty bomb by several months. This is the only change introduced in this upgrade.
The Altair upgrade was the first scheduled upgrade for the Beacon Chain. It added support for "sync committees"—enabling light clients, and bringing validator inactivity and slashing penalties up to their full values.
The London upgrade introduced EIP-1559, which reformed the transaction fee market, along with changes to how gas refunds are handled and the Ice Age schedule.
The Berlin upgrade optimized gas cost for certain EVM actions, and increases support for multiple transaction types.
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.
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.
The Muir Glacier fork introduced a delay to the difficulty bomb.
The Istanbul fork: Optimised the gas cost of certain actions in the EVM, Improved denial-of-service attack resilience, Made Layer 2 scaling solutions based on SNARKs and STARKs more performant
The Constantinople fork ensured the blockchain didn't freeze before POS was implemented, Optimised the gas cost of certain actions in the EVM and added the ability to interact with addresses that haven't been created yet.
The Byzantium fork, reduced block mining rewards from 5 to 3 ETH, delayed the difficulty bomb by a year. It also added ability to make non-state-changing calls to other contracts and added certain cryptography methods to allow for layer 2 scaling.
The Spurious Dragon fork was the second response to the denial of service (DoS) attacks on the network (September/October 2016)
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.
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. Anyone who lost funds could withdraw 1 ETH for every 100 DAO tokens in their wallets.
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.
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.
Frontier was a 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.
A total amount of 31,531 BTC was collected, worth $18,439,086 at the time of the sale, in exchange for about 60,102,216 ETH.
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, published in 2013 by Vitalik Buterin, the founder of Ethereum, before the project's launch in 2015.