Who is Marcus Tullius Cicero from Roman Blood and what is their importance?

Marcus Tullius Cicero comes from a wealthy family, although he is not a member of the nobility. He was born in Arpinum and later moved to Rome with his family. At the time of the narrative, Cicero is twenty-six, although Gordianus notes that he looks slightly older. He is of medium height, with thinning hair, a large forehead and a fleshy nose. He also has a very delicate digestive system and often forgoes food altogether. Cicero is noted to be somewhat high-strung, and he has a tendency to anger quickly. He is, however, a man of great personal discipline and decorum.