Mice of the Round Table, book 1: A Tail of CamelotJulie Leung2017

A brave mouse, a noble boy and a legendary sword.
Young mouse Calib Christopher dreams of becoming a Knight of the Round Table. For generations, his family has led the mice who live just out of sight of the humans, defending Camelot from enemies big and small. But when tragedy strikes on the night of the annual Harvest Tournament, it is up to Caleb to find the real culprit before an old rivalry with the animals of the Darkling Woods can get in the way of the truth.
With help from a human boy named Galahad, who may be the key to the mythical sword in the stone, Calib must unite the Mice of the Round Table with their former enemies. Only together will they be strong enough to save Camelot.