Naming fictional characters in historical fiction requires adhering to the usual rules: avoid multiple names beginning with the same letter, try not to pick something unpronounceable, vary the rhythms and number of syllables. But the name must also be right for the time and place, and it's surprisingly easy to get this wrong. I keep two lists of given names that I find in period sources, one for males and one for females. I've been lucky enough to find two lengthy journal articles analyzing naming patterns in Tuscany in this time period, which alerted me to some things I would not have expected, such as the scarcity of saints' names in the early part of the 13th century.
Origins of names can matter, too. I almost made the mistake of naming a character Francesco in a book set in 1216. But Francis of Assisi was still alive at that time, and the glut of Francescos who were named after him and who would appear in future generations had not yet been born. (Similarly, Luigi becomes a common name after the canonization of Saint Louis in 1297, but not before.)
With Italian, pronounceability is not the issue it is for many other times and places, but the reader unfamiliar with the Italian language can still encounter pitfalls. An example (historical, not fictional): Beatrice, Dante's beloved, is a character in my work in progress, but everyone calls her (and this is historically true) Bice. Some readers might look at that and hear BEE-uh-triss and Bice (rhymes with mice), but what I want them to hear is Bay-ah-TREE-chay and BEE-chay (rhymes with eBay). I know of no way to make this work except for a brief pronunciation note at the beginning.