Who is Gregory of Tours from The History of the Franks and what is their importance?

Gregory of Tours is the book's original author. He was a Roman and a Christian and a Gaul all at the same time. Because of his service to the Church, Gregory of Tours was canonized after his death, in part due to his having taken the task of writing the book summarized here. The reason now, is the same as it was at the time - no one else did, but he did do it.