Cardano Marks Six Years Since Shelley With 9.25 Million Blocks and No Full Network Halt

Cardano has produced approximately 9.25 million blocks since the Shelley hard fork was activated on July 29, 2020. The official Cardano account marked the sixth anniversary with figures covering 439 epochs and around 190 million slots since the network moved from Byron into the Shelley era.

Shelley enabled stake pool registration, delegation and staking rewards. It also began a staged transfer of block production to community operators, a process completed in March 2021.

Shelley Moved Cardano Beyond the Byron Era

Shelley was activated at 21:44:51 UTC at the beginning of epoch 208. Cardano had previously operated in the Byron era, when federated nodes managed by Input Output, the Cardano Foundation and EMURGO were responsible for producing blocks.

The archived announcement, “Shelley is delivered”, described a network designed to support large-scale participation by community-operated stake pools. The upgrade allowed ADA holders to delegate funds and receive staking rewards without transferring custody of their assets.

Cardano executed the transition through its Hard Fork Combinator, which allows successive protocol eras to operate as one continuous blockchain. Shelley did not create a new token or competing chain. Nodes adopted the new rules at a predetermined slot while the Byron transaction history remained part of the same ledger.

Community Stake Pools Took Over Block Production

The first allocation of blocks to community stake pools began on August 13, 2020, during the transition from epoch 210 to epoch 211. Cardano reduced its decentralization parameter, known as d, from 1.0 to 0.9, assigning ten percent of block production to stake pools.

Their share increased as the parameter was progressively reduced. According to the official Cardano documentation, d reached zero on March 31, 2021, placing all block production in the hands of community stake pools. The parameter was later removed during the Vasil upgrade because federated nodes no longer participated in the process.

In Cardano’s protocol, slots are the time intervals in which Ouroboros selects eligible stake pools to produce blocks.

Cardano did experience technical incidents during the six-year period. In November 2025, a malformed transaction exploited a deserialization issue and caused a temporary chain partition. The official incident report stated that the network remained online, funds were not at risk and complete convergence was restored within 14.5 hours.

Van Rossem Brought Mainnet Upgrades Into On-Chain Governance

Shelley decentralized block production, but protocol changes remained under the control of Cardano’s founding entities. The Chang hard fork introduced the first CIP-1694 governance functions in September 2024, while Plomin activated the full governance framework in January 2025, including DReps and on-chain processes for parameter changes, Treasury withdrawals and future hard forks.

That framework was applied to a mainnet upgrade with the activation of the van Rossem hard fork on July 18, 2026. According to an Intersect network update, Protocol Version 11 received 77.63 percent DRep support, approval from stake pool operators representing 52.7 percent of active stake and support from six Constitutional Committee members.

Van Rossem introduced new ledger rules, VRF key uniqueness requirements, Plutus performance improvements and additional cryptographic functions. It became the first Cardano mainnet upgrade in the full governance era to receive approval from all three on-chain governance bodies.

Under the system operating six years after Shelley, ADA holders delegate without surrendering custody, community stake pools produce blocks, and mainnet upgrades require approval from DReps, stake pool operators and the Constitutional Committee. Van Rossem became the first Cardano mainnet upgrade authorized through that full governance framework, extending the 2020 transition from block production to the rules governing future protocol changes.