Glossary
London Hard Fork
The August 2021 Ethereum upgrade that introduced EIP-1559 — replacing the prior gas-price auction with a burned base fee plus an optional priority tip.
The London hard fork activated on block 12,965,000 (August 5, 2021) and shipped five EIPs, the most consequential being EIP-1559. The upgrade replaced Ethereum's first-price gas auction with an algorithmically-set base fee (burned, not paid to the miner) plus an optional priority tip.
EIP-1559 made gas prices more predictable and introduced ETH burn as a structural counterweight to issuance. The London fork is widely viewed as a milestone in Ethereum's monetary policy evolution and a major piece of the post-Merge "ultra-sound money" narrative.