The Blocksize War

The Blocksize War chronicles Bitcoin’s constitutional crisis: the 2015–2017 conflict over whether to scale by raising the block size. Bier reconstructs the escalation — BitcoinXT, Classic, Unlimited, the Hong Kong and New York agreements, UASF, and the SegWit2x collapse — from primary sources and interviews, largely without editorializing, letting the participants’ own moves reveal the stakes.

The war’s outcome settled the deepest question in the system: who controls Bitcoin’s rules? Not miners, not companies with agreements, but the users who run validating nodes. The book is the definitive record of how that was established in practice, not just in theory.

It suits anyone who wants to understand Bitcoin governance — which is to say, anyone who wants to understand why the 21 million cap is credible. Newcomers can read it as a thriller; veterans will argue with its emphases, which is the mark of a fair history.