|Also known as||The Beast|
|Relatives|| Fiona Chatwin (younger sister)|
Rupert Chatwin (younger brother)
Helen Chatwin (younger sister)
Jane Chatwin (younger sister)
|Occupation||High King of Fillory (former)|
| Spoiler warning!|
This article contains plot details.
Aunt Maude's House
Martin Chatwin was the eldest of the Chatwin Children. He was sent, along with his siblings, to his Aunt Maude's house, during World War I. During a party that Aunt Maude was hosting, he was attempting to understand a (possibly magical) grandfather clock, when He entered Fillory via a portal inside of it. Fiona follows him in the clock, and then the events of The World In The Walls occurred. From Rupert Chatwin's perspective he reappeared shortly after entering the grandfather clock. They were wearing different clothes, looked more suntanned and fit, and their hair has grown longer.
In The Magicians, the Chatwin Children are rumored to have been real and to have lived next door to the author, Christopher Plover. Martin finds a way to remain in Fillory forever, and Quentin makes it his mission to find Martin, if he is still alive. It turns out, however, that although Martin is alive, the secret behind his stay in Fillory is darker than the Physicals could have imagined.
Fillory chooses who enters her borders and who doesn't. As Martin grows older, it doesn't call him anymore. Martin grows increasingly annoyed by his apparent banishment from Fillory. With help from Rupert and some magic of his own, he gets into Fillory anyway and sells his humanity to Umber for the power to stay in Fillory forever.