The man behind the story of Father Christmas or Santa Claus is Saint Nicholas who was a bishop that lived in Myra which is now the modern day Turkey. He was said to be wealthy and a generous Bishop.
There are many stories of how Santa Claus came about; the most popular one is about how St. Nicholas saved the daughters of a man from being sold to slavery.
In the early USA his name was Kris Kringle (which means Christ kind). Later, some Dutch settlers in the US took the story of St. Nicholas with them. Kris Kingle and St. Nicholas became “Sinterklaas” which is what we now know as Santa Claus.