The moments Ethereum changed

• Hegotá (2027 (per Strawmap)): Focil (Fork-Choice Enforced Inclusion Lists, FOCIL), which resists censorship, and frame transactions, which make account abstraction a native transaction type, are the headliners.
• Glamsterdam (Early 2027 (per Strawmap)): The roles of the builder who constructs the block and the validator who selects it are separated inside the protocol (ePBS), and the state a block will touch is declared in advance, opening the way to parallel execution (BAL).
• Fusaka (2025-12-03): PeerDAS, where nodes verify a sample of blob data instead of downloading all of it, greatly expanded the data space available to L2s. BPO forks, which raise only the blob count, widen that space in steps afterward.
• Pectra (2025-05-07): Regular wallets (EOAs) can behave like smart accounts, and the staking limit a single validator can carry was raised from 32 ETH to 2048 ETH.
• Dencun (2024-03-13): Blobs, which let rollups post data cheaply, were introduced and sharply lowered L2 fees.
• Shapella (2023-04-12): Staked ETH and rewards became withdrawable.
• The Merge (2022-09-15): Proof-of-work mining ended and Ethereum moved to proof of stake. Ethereum's energy use fell by more than 99%.
• Gray Glacier (2022-06-30): The difficulty bomb was delayed.
• Arrow Glacier (2021-12-09): The difficulty bomb was delayed.
• Altair (2021-10-27): The first upgrade of the Beacon Chain. It supported light clients through sync committees and reworked the inactivity penalty.
• London (2021-08-05): Fees were split into a base fee and a tip, and the base fee began to be burned. Fees became easier to predict and ETH issuance began to be offset.
• Berlin (2021-04-15): State access gas costs were adjusted, and a framework (typed transactions) that can hold multiple transaction formats was created.
• Beacon Chain launch (2020-12-01): The proof-of-stake consensus chain began running separately from mainnet. It merged with mainnet two years later in The Merge.
• Muir Glacier (2020-01-02): The difficulty bomb was delayed.
• Istanbul (2019-12-08): Gas costs were adjusted, and the chain ID opcode and lower precompile prices were added.
• Constantinople (2019-02-28): CREATE2, which allows addresses to be determined in advance, and bit shift opcodes were added, and the block reward was cut to 2 ETH.
• Byzantium (2017-10-16): Zero-knowledge proof verification precompiles and REVERT were added, and the block reward was cut to 3 ETH.
• Spurious Dragon (2016-11-22): The chain ID was included in signatures to prevent their reuse on other chains (replay), and empty accounts were cleaned up.
• Tangerine Whistle (2016-10-18): Gas costs of opcodes that were being abused for DoS attacks were raised.
• The DAO Fork (2016-07-20): A state change that returned the funds drained in The DAO hack. Those who opposed it continued as Ethereum Classic.
• Homestead (2016-03-14): The first production upgrade after launch. It refined transaction signature rules and gas calculation.
• Frontier (2015-07-30): The launch of the Ethereum mainnet.