The following timeline documents the formative events that created and defined Ethereum Classic, and all major events to the present day.
For a more detailed investigation into the creation of ETC, please check out Genesis.
Vitalik Buterin and The Ethereum Foundation created the first blockchain-based Turing-complete smart contract platform with the Frontier release.
The network implements an ‘Ice Age’ at block 200,000 introducing the Difficulty Bomb, a mechanism designed to move the network's consensus mechanism away from Proof-of-Work to Proof-of-Stake.
Slock.it constructs The DAO Ethereum Contract; a security audit is completed by Dejavu.
The DAO smart contract is deployed; members of the public send it value in return for DAO tokens.
Slock.it announces a $1.5 Million USD proposal, paid in Ether by the crowdfund, 'to guarantee the integrity of The DAO'.
On the last day of the crowdsale, DAO curator Vlad Zamfir calls for a moratorium on The DAO, citing many game-theoretical security issues.
The crowdsale completes to become the world's largest and raising an incredible $150 Million USD.
Peter Vessenes publicly discloses the existence of a critical security vulnerability overlooked in many Solidity contracts.
Stephan Tual publicly claims that The DAO funds are safe despite the newly-discovered critical security flaw.
The price of Ether is slashed in half as Griff Green announces that The DAO has been hacked.
The DAO's splitting mechanism gives around a month for a solution to be found that recovers the funds; Foundation and community developers race to implement a soft fork.
A group of 'white-hat' hackers secure 70% of The DAO funds but protocol-level action is required to save the remaining 30% split by the hacker.
The Ethereum Foundation releases a 'Soft Fork' client to censor transactions coming from the hacker; mining pools vote to enable it by lowering gas limit.
Critical Denial of Service flaws are found in the Soft Fork implementation, miners quickly decide NOT to use it.
Many days of intense arguing goes on in the Ethereum community about the pros and cons of implementing a Hard Fork.
The only remaining option is a controversial Hard Fork. A Specification is determined and announced by Slock.it and Ethereum Foundation members.
With 12 hours notice, The Ethereum Foundation use a controversial third party 'coin vote' to determine that the Hard Fork should be turned on by default; consensus is declared, and an updated client is released.
With around 80% of nodes updating to the new client, the community nervously await the arrival of the DAO Bailout fork activation block 1,920,000.
A forked-chain is born! The Ethereum Foundation creates an altered version of Ethereum on July 20 2016 to reverse the DAO theft. As trademark rights holders, the Ethereum Foundation applies the Ethereum (ETH) brand to the new forked chain.
With predictions of the original non-forked chain to disappear within hours, many are surprised to find that miners continue to support the original chain. Bisq and OTC desks give these tokens a price discovery order book. The markets participants rebrand this non-forked chain Ethereum Classic (ETC).
The ETH community lets out a sigh of relief as the DAO fork code is successfully implemented with no obvious flaws; champagne corks are popped all over the globe. The birth of a new chain is a success!
The largest Ethereum exchange signals long-term support for the original chain, Poloniex lists ETC. Many exchanges quickly follow suit.
The Flame Wars begin in subreddits. As economically-charged vitriolic spats begin to take hold of the participants as it comes to terms with the reality of the split.
The Ethereum Classic supporters branch off from Ethereum subreddits and form their own social channels.
Geth releases support for Ethereum Classic network. This node has all the DAO code removed from the client and requires no additional flags to use the Ethereum Classic network.
Parity signals long term support for Ethereum Classic with 1.2.3 release that addresses network stability issues for both Ethereum HF and Ethereum Classic chains and brings a few changes to the transaction tracing API.
ETH supporters form a mining pool called 51Pool.org with plans to destroy the ETC network by orchestrating a 51% attack.
After the ETC network grew to a point where they could no longer attack it, ETH miners publicly declare not to attack ETC. To prevent hurting innocent Ethereum Classic holders, ETHash miners commit resources to mining ETC.
The Robin Hood Group attempts to market dump a large quantity of stolen ETC from the DAO fork. Poloniex freezes their funds.
After relentless attacks from the ETH side of the chain split, Ethereum Classic supporters stand firm and declare their independence from the new ETH chain.
Ethereum Classic proves its resilience to the markets as ETC emerges from the ETH attacks with a stabilizing price. The networks core principles are galvanized during the DAO Bailout. Supporters begin rebuilding from the ashes.
Millions of previously locked or frozen ETC become available to DAO token holders and the DAO hacker. ETC's price holds remarkably well in face of huge market dumps.
During the ETH attacks, many battle cries come out of Ethereum Classic supporters. They begin to clarify their core principles and validate the ETC network existence to the public.
Both Ethereum networks are attacked due to vulnerabilities in the tech stack. ETC devs quickly ensure a smooth and non-contentious network upgrade to patch exploited vulnerabilities.
Ethereum Classic addresses replay attacks and delays the difficulty bomb in a network upgrade.
Ethereum Classic forms consensus around a 210.7M ETC fixed-cap monetary policy with a Bitcoin-inspired limited emission schedule called 5M20; 20% block reward reduction every 5M blocks.
Grayscale launches the first non-bitcoin crypto fund enabling traditional investors to add ETC to their portfolio with the all the tax benefits of a traditional investment asset.
The release of this beta client, Mantis, will take place today and is the culmination of seven months of work by the Grothendieck Team, the IOHK developers dedicated to Ethereum Classic.
Grayscale signals long-term support for Ethereum Classic protocol development by sponsoring the ETC Cooperative team with a portion of their ETCG management fees. Donations to the non-profit are tax-deductable.
The Gotham upgrade established a predictable monetary policy and emission schedule inspired by Bitcoin. 5M20, the block reward will reduce by 20% every 5M blocks.
Ethereum Classic's 5M20 emission schedule enters Era 2. Block rewards are reduced by 20% to 4 ETC per block.
The Multi-Geth client project launches. This is a go-ethereum client forked from Ethereum Foundation's version, aimed to follow closely for upstream changes, and support multiple Ethereum networks. We have just added alpha support for Ethereum Classic network.
ETC safely disables the difficulty bomb to switch the original Ethereum project to PoS. Ethereum Classic signals long-term commitment to Proof of Work as a network consensus mechanism.
Ethereum Classic Labs provides funding, industry connections, and office space to burgeoning ETC projects; with office space in San Francisco and Singapore.
ETC Cooperative funds the development of the Kotti testnet, a Proof-of-Authority testnet constructed to provide interoperability testing with sister-chain ETH's Görli Testnet. PoA becomes the preferred testnet environment for dapp development testing.
The largest cryptocurrency exchange in the USA signals long-term support for the original Ethereum chain; Ethereum Classic.
Ethereum Classic Labs launches an incubator program. ETC Labs commits to work with as many as 24 Ethereum Classic based startups each year.
Ethereum Classic experiences the first successful chain reorganization attack on its network. The resilient ETC rises from the ashes.
The 51% attacker appears to be a whitehat hacker and returns stolen funds to a compromised exchange. Centralized exchanges tighten 51% attack monitoring on Proof of Work coins across the board.
Ethereum Classic core developers reach rough consensus on ECIP-1054 in an effort to implement ETH's Spurious Dragon and Byzantium network protocol upgrades.
Ethereum Classic core developers implement ETH's Spurious Dragon and Byzantium network protocol upgrades to maintain operational parity with its sister chain.
Core developers removed testnet redundancy by replacing Kensington, Morden, and Nazgul test networks with Mordor, an Ethash PoW testnet for protocol level testing.
Hyperledger Besu adds Ethereum Classic support to their Ethereum client designed to be enterprise-friendly for both public and private permissioned network use cases.
Ethereum Classic core developers reach rough consensus on ECIP-1061 in an effort to implement ETH's Istanbul network protocol upgrade.
Ethereum Classic core developers reach rough consensus on ECIP-1056 in an effort to implement ETH's Constantinople and Petersburg network protocol upgrades.
Ethereum Classic core developers implement ETH's Constantinople and Petersburg network protocol upgrades to maintain operational parity with its sister chain.
The ETC Core team forks away from the Multi-Geth client project. The project is named Core-Geth, an ethereum/go-ethereum downstream effort to make the Ethereum Protocol accessible and extensible for a diverse ecosystem.
During Aztlán testnet implementations, Ethereum Classic core developers discover complications with ECIP 1061 specs to add ETH's Istanbul network protocol upgrade. As intended, the ETC testnets catch the issues and core developers spec a patch for the issues.
ECIP 1050 Status Codes moves to Final status. This standard outlines a common set of Status Codes in the same vein as HTTP statuses. This provides a shared set of signals to allow smart contracts to react to situations autonomously, expose localized error messages to users, and so on.
During Aztlán testnet implementations, Ethereum Classic core developers discover complications with ECIP 1061 and 1078 specs to add ETH's Istanbul network protocol upgrade. Meowbits of ETC Core documents the findings. As intended, the ETC testnets catch the issues and core developers go back to the drawing board.
Based on the issues discovered during Aztlán testnet implementation, Phoenix Fix being found to not be a sufficient fix and both testnets breaking; the Core developers proposes to reject ecips-1061, 1078, 1086 due to security and stability concerns and to move on with writing a new proposal from scratch.
Ethereum Classic core developers reach rough consensus on ECIP-1088 in an effort to implement ETH's Istanbul network protocol upgrade. Testnet implementations revealed issues with prior attempts in specs ECIP-1061 and ECIP-1078.
Phoenix testing begins on the Mordor PoW testnet on block 999,983. Core development teams have signaled that this is a complex implementation. Testing may uncover issues that delay this network upgrade, but Ethereum Classic will never rush to upgrade the mainnet. Network security is priority over development speed and arbitrary timelines.
Ethereum Classic's block rewards are reduced by 20% to 3.2 ETC per block, as per the bitcoin-inspired 5M20 emission schedule.
Phoenix testing begins on the Kotti PoA testnet on block 2,200,013. Core development teams have signaled that this is a complex implementation. Testing may uncover issues that delay this network upgrade, but Ethereum Classic will never rush to upgrade the mainnet.
Ethereum Classic core developers implement ETH's Istanbul network protocol upgrades to maintain operational parity with its sister chain.
On the 4th anniversary of the DAO Bailout Hard Fork, ETH-centric client maintainers orchestrate a social attack on Ethereum Classic. The client maintainers announce deprecation of Ethereum Classic support, then execute a misinformation marketing campaign citing the ETC network would lose 70% of the hashrate among other untruths.
Ethereum Classic experiences the second successful chain reorganization attack on its network.
Ethereum Classic experiences the third successful chain reorganization attack on its network.
Ethereum Classic experiences the fourth successful chain reorganization attack on its network.
The Core-Geth client implements the flags to apply the optional M.E.S.S. functionality as a response to the Ethereum Classic networks' 51% attacks.
Ethereum Classic implements the Thanos Upgrade to recalibrate the epoch length used in DAG calculations.
Ethereum Classic implements the Thanos Upgrade to adjust the mining algorithm from ETHash to ETCHash.
Input Output Global signals support for the Ethereum Classic network with the revival of the Mantis client and GUI.
The Geth exploit software bugs that split the Ethereum Foundation mainnet in August, 2021 splits the Ethereum Classic mainnet. Everyone is advised to update their clients.
A concerned ETC participant penned a long rebuttal that argued against the implementation of ECIP-1098.
After a year long discussion about whether a ECIP-1098 would gel with ETC values, ETC Coop, followed by IOHK withdraw support for a Treasury Proposal at the network level.
Ethereum Classic core developers implement ETH's Berlin network protocol upgrades to maintain operational parity with its sister chain.
Ethereum Classic core developers implement ETH's London network protocol upgrades to maintain operational parity with its sister chain.
ETC Welcomes New Hashrate
Ethereum Classic commits support to the ETChash mining algorithm and the current mining ecosystem. This positions Ethereum Classic as a network well positioned to absorb a majority of the disenfranchised Ethash miners with ETH network's move to proof of stake consensus.
Stable and long-term funding proves to be a problem for Ethereum Classic with abandonment by the Ethereum Foundation in 2016. In an effort to solve the network's LTS funding issue, Ethereum Classic DAO is formed with a mission to future proof the network's development via an open source development fund. Funding is generated with use of an ETC DeFi stack hosted at EthereumClassic.com
Ethereum Classic's block rewards are reduced by 20% to 2.56 ETC per block, as per the bitcoin-inspired 5M20 emission schedule. ETChash mining hashrate continues to turn over to ETC with the network reaching All-Time Highs.
After more than three years of contentious debate, Bob Summerwill acknowledges the contentious hardfork ECIP-1049 would cause on the network and withdraws the proposal. The negative social cost caused by the ECIP-1049 proponent's misinformation campaign continues to negatively affect the network's public perception. However through its resilient community, Ethereum Classic remains well-positioned to thrive on ETChash in a post-merge world.
Ethereum Classic DAO launches its first product- ETCswap. This ensures the network is one step closer to stable funding for open source development on Ethereum Classic. A professional decentralized protocol stack will be deployed on Ethereum Classic.
Vitalik Buterin, Ethereum's most prominent co-founder, gives an endorsement of the original Ethereum network-- Ethereum Classic for those who value Proof-of-Work chains.
AntPool supports Ethereum Classic ecosystem with $10M Investment. Antpool seeds a treasury fund with a goal of supporting the professional development ecosystem on Ethereum Classic.
As the upcoming Ethereum merge continues to cause excitement within the crypto space, Ethereum Classic (ETC), a sister of Ethereum, has seen an 83% increase in hashrate since June, 2022.
Days before the Merge, Charles Hoskinson publicly signals intent to "repurpose" the Ethereum Classic's main twitter account. He justifies this action due to sunk costs in the undelivered Mantis client and rejection of IOHK's 2021 centralized treasury proposal (ECIP-1098).
ETH's Move to Proof of Stake
The Ethereum Foundation upgrades the largest EVM network to proof-of-stake consensus. This Merge event cements Ethereum Classic as the largest Proof of Work EVM network. Ethereum Classic's network security elevates as it becomes the apex network of all Ethash derivative mining algorithms. The Phoenix rises.
Fall out from the ETC community's social rejection of IOHK's centralized treasury in 2021, Charles Hoskinson transfers the Ethereum Classic's main Twitter account to a third-party open source project called Ergo. The Ergo team rebrands the account to their own project. Bob Summerwill is sent a newly registed Twitter account with the main Twitter accounts twitter handle with 0 history and 0 followers.
A Bright Future
As the ecosystem continues to organically grow, the independent development teams and network participants are guided by principles that make Ethereum Classic such a unique network. The network is truly decentralized, immutable, and unstoppable. Code is law.