Once upon a time, in a world ruled by banks, every coin a person owned lived inside a great stone counting-house. To pay a friend, you asked the counting-house. To send money across the sea, you asked the counting-house, and waited, and paid a toll.

The keepers of the counting-house wrote everything in one enormous ledger, and only they could hold the pen. Most days, people trusted them. But in the autumn of 2008, the ledgers of the mightiest houses cracked.

On 15 September 2008, the bank Lehman Brothers fell, and the whole kingdom of finance shook. Governments rushed to rescue the banks with bailouts paid for by ordinary people.

Many folk began to ask an old, dangerous question: what if money did not need a counting-house at all? Clever people had asked it before — David Chaum with his eCash, Adam Back with Hashcash, Wei Dai with b-money, Nick Szabo with bit gold — but no one had quite made the answer work.

On 31 October 2008, a person — or perhaps a group — calling themselves Satoshi Nakamoto posted a short paper to a small mailing list of cryptographers. Its title was plain: Bitcoin: A Peer-to-Peer Electronic Cash System.

It was only nine pages long. It described money that could be sent directly from one person to another, without going through a financial institution. Instead of one keeper with one pen, thousands of computers would keep the ledger together, and agree on it through a puzzle-solving race called proof of work.

On 3 January 2009, Satoshi mined the very first block — the genesis block — and hid a message inside it, a headline from The Times of London: “Chancellor on brink of second bailout for banks.” It was a timestamp, and a quiet protest.

Days later, on 12 January 2009, Satoshi sent 10 bitcoin to a programmer named Hal Finney — the first person-to-person bitcoin payment ever recorded.

Every ten minutes or so, a new page — a block — is added to the notebook. Each page carries a fingerprint of the page before it, so tearing one out would smudge every page after. That is the chain.

Only 21 million bitcoin will ever exist; the reward for adding a page halves roughly every four years. And on 22 May 2010, Laszlo Hanyecz paid 10,000 bitcoin for two pizzas — proof that this strange new money could buy something real.

Around the end of 2010, Satoshi quietly stepped away and was never heard from publicly again. The notebook kept writing itself. No one owned it — and that was the whole point.