For a century, films have ended on the word 'Fin' — Finn is the name this story begins with

Where Finn comes from and what it means

Finn is the anglicised form of the Irish Fionn, and it means 'fair', 'white' or 'bright'. The name's first famous owner set the bar absurdly high: Fionn mac Cumhaill, the great hunter-warrior of Irish legend and leader of the Fianna. As a boy, the story goes, he was cooking the Salmon of Knowledge for his master, burnt his thumb on its skin, put the thumb in his mouth — and swallowed all the wisdom in the world along with it. Irish tradition also credits him with building the Giant's Causeway, the tens of thousands of basalt columns still standing on the Antrim coast. Not many four-letter names come with their own geology.

The Norse were fond of it too: Finnr appears as a personal name throughout the old sagas, carried across the North Sea by Vikings — which is partly why the name feels equally at home in Dublin, Oslo and Hamburg today.

For most of the twentieth century, English-speaking parents left Finn to the legends. Then, around the turn of the millennium, it appeared on the charts — and it has climbed ever since. In Germany and the Netherlands, Finn has spent recent years among the most popular boys' names in the whole country; in Ireland, Britain, America and Australia it has moved from rare to firmly beloved. Writers never needed convincing: Mark Twain gave the name to the most famous boy on the Mississippi, and screenwriters have been reaching for it ever since, from animated adventurers to a Star Wars hero. A boy named Finn today shares his name with legends — but only rarely with a classmate.

What Finn gets called at home

• Finn — The everyday name and the Sunday-best name in one. Plenty of names save a short form for the playground; Finn is both at once — which is why it is the form that belongs on the cover and in every line of the story.
• Finny — The toddler-years form, mostly a parents' privilege — said over a cot, a grazed knee or a bowl of porridge. Most boys grow out of it by school age; most parents never quite do.
• Fin — The name pared down to its last three letters — how siblings shout it up the stairs and how his friends will one day text it. It loses a letter and keeps all of the sound.
• Fionn — The original Irish spelling, pronounced exactly the same. Families who chose it in honour of the legend should enter it exactly so — the book prints the name letter for letter, just as you type it.
• Finn as the short form — For boys formally named Finnegan, Finley, Fintan or Phineas, Finn is the form that actually gets used at the dinner table. If that is your Finn, put Finn in the book — a hero should be called what he answers to.