Knights of Art by Amy Steedman

Nowhere in Florence could a more honest man or a better worker be found than Agnolo the tailor. True, there were once evil tales whispered about him when he first opened his shop in the little street. It was said that he was no Italian, but a foreigner who had been obliged to flee from his own land because of a quarrel he had had with one of his customers. People shook their heads and talked mysteriously of how the tailor's scissors had been used as a deadly weapon in the fight. But ere long these stories died away, and the tailor, with his wife Constanza, lived a happy, busy life, and brought up their six children carefully and well.

Now out of those six children five were just the ordinary commonplace little ones such as one would expect to meet in a tailor's household, but the sixth was like the ugly duckling in the fairy tale -- a little, strange bird, unlike all the rest, who learned to swim far away and soon left the old commonplace home behind him.