Who is Satoshi Nakamoto?

The pseudonym of the person or group who invented Bitcoin. Who is behind it is unknown. In 2024, a UK court ruled that Craig Wright, who had claimed for years to be Satoshi, is not.

Why is 22 May ‘Bitcoin Pizza Day’?

On 22 May 2010, a forum user reported that he had exchanged 10,000 BTC for two pizzas – one of the first documented purchases of goods with bitcoin.

Is Bitcoin Cash the same as Bitcoin?

No. Bitcoin Cash split off in 2017 and has been a separate currency with its own rules ever since. The name alone doesn’t make it bitcoin.

What does the headline in the genesis block mean?

It quotes the London Times of 3 January 2009 about an imminent second bank bailout and proves that the block was not created before that day. It is often read as a comment on the financial crisis – Satoshi never explained it.

The history of Bitcoin

Bitcoin is not yet twenty years old. Its key milestones explain why it works the way it does today – and why disputes over its rules are taken so seriously.

The timeline at a glance

31 October 2008
The whitepaper is published
Satoshi Nakamoto presents ‘Bitcoin: A Peer-to-Peer Electronic Cash System’ on a cryptography mailing list.^[1]
3 January 2009
The genesis block
The first block of the chain is created – with a newspaper headline about bank bailouts inside it.^[2],[6]
9 January 2009
Version 0.1 of the software
Satoshi releases the first program that allows anyone to take part in the network.^[3]
12 January 2009
The first transfer
In block 170, Satoshi sends 10 BTC to the cryptographer Hal Finney.^[6],[4]
22 May 2010
Bitcoin Pizza Day
10,000 BTC change hands for two pizzas.^[7]
12 December 2010
Satoshi withdraws
Satoshi’s last post in the Bitcoin forum.^[5]
February 2014
Collapse of Mt. Gox
What was then the largest trading platform halts withdrawals and files for bankruptcy.^[8]
August 2017
Bitcoin Cash splits off, SegWit activates
On 1 August 2017, Bitcoin Cash emerges as a separate chain.^[10] On Bitcoin, SegWit is activated on 24 August 2017.^[9]
7 September 2021
El Salvador makes Bitcoin legal tender
The first country in the world to do so. In early 2025, the law is watered down considerably.^[12]
14 November 2021
Taproot activates
The upgrade from block 709,632 makes more complex spending conditions more efficient and more private, among other things with Schnorr signaturesGlossarySchnorr signatureA digital signature scheme that Bitcoin introduced with Taproot in 2021, alongside ECDSA. Schnorr signatures are compact (64 bytes), provably secure and can be combined into a single joint signature.In the glossary →.^[11],[6]
10 January 2024
US securities regulator approves spot Bitcoin ETPs
Since then, exchange-traded products that hold real bitcoin can be traded in the US through an ordinary securities account.^[13]
20 April 2024
The fourth halving
With block 840,000, the reward for new blocks falls from 6.25 to 3.125 BTC – as provided for every 210,000 blocks since 2009.^[6],[2] The next halving follows at block 1,050,000, by today’s estimate around March 2028. More in The halving & the 21 million.
10 October 2025
Bitcoin Core 30 relaxes data filters
The most widely used node software relays larger data attachments (OP_RETURN) by default – a fiercely contested step.^[14]
8 August 2026
Chain split over BIP-110
A minority splits off to restrict data in transactions. At first, its chain finds hardly any blocks.^[15],[6]

The beginnings (2008–2010)

Digital cash was not a new idea in 2008. What was new was Satoshi’s combination: a peer-to-peerGlossaryPeer-to-peer (P2P)‘Between equals’: participants exchange data or money directly with one another, without a central intermediary. In Bitcoin, nodes pass transactions and blocks directly to each other.On the learning path: Stage 1 · Step 3 – How does Bitcoin work? →In the glossary → network prevents double spending without a mint or any other trusted party. New coins are created through computing work, modelled on an older method called Hashcash.^[1] What the whitepaperGlossaryWhitepaper (Bitcoin whitepaper)The nine-page founding document in which Satoshi Nakamoto introduced Bitcoin on 31 October 2008. It explains how payments can work without a bank and how double spending is prevented.In the glossary → says is explained in The Bitcoin whitepaper explained.

The genesis blockGlossaryGenesis blockThe very first block of the Bitcoin blockchain, created on 3 January 2009. It contains a newspaper headline about bank bailouts – and its reward of 50 BTC can never be spent, for technical reasons.In the glossary → contains a headline from the London Times of 3 January 2009 about an imminent second bank bailout. It is still stored in the Bitcoin Core source code today.^[2] Technically, it proves that the block was not created before that day. Many read it as a comment on the financial crisis – Satoshi never explained it. This is what the message looks like in the block, as bytes and as text:

block 0 · coinbase · 3 Jan 2009 18:15:05 UTC

“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”

These bytes have been stored immutably in the very first Bitcoin block since 3 January 2009. After 8 technical bytes (grey) comes that day’s front-page headline of London’s “The Times”: the Chancellor is on the brink of a second bank bailout.

The first person besides Satoshi to use the software, report bugs and improve it was the cryptographer Hal Finney (1956–2014).^[3]

What a bitcoin is worth still had to be established. On 18 May 2010, the forum user ‘laszlo’ offered 10,000 BTC for two large pizzas; on 22 May 2010, he reported the trade.^[7] Worked example: at $80,000 per BTC, those 10,000 BTC would be worth $800 million (current price: $85,533).

Satoshi’s withdrawal

Until mid-2010, Satoshi made all changes to the source code personally, then handed the code repository over to the developer Gavin Andresen.^[3] The last forum post, on 12 December 2010, was a technical note on version 0.3.19.^[5] In 2011, Satoshi wrote to the developer Mike Hearn that he had moved on to other things. After that, the trail goes cold.^[3]

Who is behind the pseudonym Satoshi NakamotoGlossarySatoshi NakamotoPseudonym of the person or group who invented Bitcoin. Satoshi published the whitepaper in 2008, launched the network in 2009 and withdrew in 2011. Who is behind the name remains unknown to this day.In the glossary → is unknown. In 2024, a UK court ruled that Craig Wright, who had claimed for years to be Satoshi, is not; according to the judgment, the documents he submitted as evidence were forged. Satoshi is credited with an estimated 750,000 to 1.1 million BTC from the early days.^[3]

The hard lesson: Mt. Gox (2014)

From April 2013 into 2014, more than 70% of global bitcoin trading went through Mt. GoxGlossaryMt. GoxA Japanese Bitcoin exchange that collapsed in February 2014. Around 850,000 BTC were missing; just under 200,000 turned up again. Since July 2024, the trustee has also been repaying creditors in bitcoin; the current deadline is 31 October 2026.On the learning path: Stage 5 · Step 1 – Understanding custody →In the glossary → in Tokyo.^[8] Then things moved fast:

7 February 2014: Mt. Gox halts all bitcoin withdrawals.
24 February 2014: the website goes offline.
28 February 2014: Mt. Gox files for bankruptcy protection in Tokyo.
Around 850,000 BTC are missing, about 750,000 of them belonging to customers. Just under 200,000 BTC later turn up in an old wallet.^[8]

According to a later investigation, most of the coins had been stolen bit by bit from the exchange’s online wallet since as early as late 2011.^[8] Customers only saw a balance in the company’s database. Whether the bitcoin behind it still existed, they had no way of checking.

This is exactly what the rule ‘Not your keys, not your coinsGlossaryNot your keys, not your coinsA guiding principle of the Bitcoin community: if you don’t hold the private keys yourself, you don’t own your bitcoin directly – you only have a claim against the custodian. Exchange collapses such as Mt. Gox and FTX show why.On the learning path: Stage 5 · Step 1 – Understanding custody →In the glossary →’ warns about: if you don’t hold the keys yourself, you depend on the platform. Understanding custody explains what this means for you; for the status of repayments to creditors, see What’s changing right now.

Disputes over the rules: 2017 and 2026

For a long time, Bitcoin blocks were limited to 1 MB.^[9] As usage grew, one side wanted larger blocks for more transactions and lower fees. The other wanted small blocks, so that as many people as possible can run their own full nodeGlossaryFull nodeA node that checks every block and every transaction itself against all the consensus rules. If you run a full node, you don’t have to trust anyone to know whether a payment is valid.In the glossary →. In 2017, the dispute ended like this:

On 1 August 2017, the proponents of large blocks split off. From block 478,559, this created Bitcoin Cash, a separate currency with blocks of initially 8 MB.^[10]
On Bitcoin, SegWitGlossarySegWit (Segregated Witness)A 2017 soft fork that treats signature data (the ‘witness’) separately. It fixed transaction malleability, increased block capacity and makes payments with modern addresses (bc1q…) cheaper.In the glossary → became active on 24 August 2017 at block 481,824. It creates more space without directly lifting the old limit.^[9],[2]
The doubling of the block size planned as a compromise (‘SegWit2x’) was called off on 8 November 2017 for lack of consensus.^[9]

For some years now, there has been a dispute over data in the blockchain, such as images and text in transactions. One side says: whoever pays the fee may use the space. The other says: such data clogs up the network and makes payments more expensive.^[15] Since version 30 (10 October 2025), Bitcoin Core relays larger OP_RETURNGlossaryOP_RETURNA command in Bitcoin’s scripting language that marks a transaction output as provably unspendable. It lets data be written into the blockchain. How much of it nodes should relay has been hotly disputed since 2025.In the glossary → data by default. That is a default setting for relaying and mining, not a rule about what counts as valid.^[14]

The BIP-110 proposal, by contrast, aimed to restrict data for around a year by means of a consensus rule.^[16] It needed 55% of blocks in support; in the two weeks before the deadline, it had 2.53%. Even so, the BIP-110 nodes split off from block 961,632 on 8 August 2026. Their chain found two blocks in around eight hours; the main chain found 48.^[15],[6] For everyone who did nothing, Bitcoin simply carried on.

Both episodes show the same thing: rules change only with broad agreement. Anyone who wants to change them unilaterally ends up on a chain of their own. Background and the arguments on both sides: Forks & controversies.

Bitcoin in the world: El Salvador and ETPs

On 9 June 2021, El Salvador’s parliament voted to make Bitcoin legal tender, with 62 of its 84 members in favour; the law came into force on 7 September 2021. Anyone who used the state wallet ‘Chivo’ received bitcoin worth $30. In everyday life, Bitcoin hardly caught on: according to the central bank, only 1.9% of remittances from abroad between September 2021 and April 2022 went through bitcoin.^[12]

In early 2025, the law was amended as part of a $1.4 billion loan from the International Monetary Fund: merchants no longer have to accept bitcoin, taxes can no longer be paid in bitcoin, and the state is withdrawing from Chivo.^[12]

On 10 January 2024, the US securities regulator SEC approved several spot Bitcoin ETPsGlossaryETP (Exchange Traded Product)Umbrella term for exchange-traded securities such as ETFs, ETCs and ETNs. With a Bitcoin ETP, you hold a security that tracks the price – but no bitcoin keys of your own.On the learning path: Stage 4 · Step 1 – Ways to get Bitcoin →In the glossary → for trading. The then SEC chair Gary Gensler stressed that this was not an endorsement of Bitcoin and warned of the risks.^[13] What such products mean for investors in Europe is explained in Bitcoin ETPs in your securities account.

Quick check

What was the most important lesson from the collapse of Mt. Gox in 2014?

What’s next?

How does Bitcoin work?What lies behind blocks, transactions and nodes technically.Forks & controversiesSoft forks, hard forks, the block size war and BIP-110, explained neutrally.Understanding custodyWhat Mt. Gox means for how you keep your own bitcoin.