CESAR1. The family name of the clan Julia, applied most generally to Julius Caesar. The Monk refers to Julius Caesar (c. 100-44 B.C.) once as "Cesar" in an apostrophe in his tragedy, MkT 2679. He says that his sources are Lucan, Suetonius, and Valerius. July is named after Julius Cesar, Astr I.10.9, who introduced the Julian calendar and named the seventh month after himself in 44 B.C. [Julius: Lucan: Pompe: Socrates: Swetonius: Valerie]
Cesar is the medieval Latin and OF form.