Publius Aelius Hadrianus was a Roman Emperor who ruled from AD 117 to 138. He is known for his travels through the Roman Empire and for building the famous Hadrian's Wall in Britain. Although many people refer to him simply as Hadrian, there are several different ways to refer to him using synonyms. These include Aelius Hadrianus, Hadrianus Augustus, Imperator Hadrianus, and Hadrianus Caesar. Each of these names highlights a different aspect of his rule, whether it be his family name, his title as emperor, or his military accomplishments. Regardless of what name he is given, Hadrian remains an important figure in Roman history.