Worship of the Roman Emperor as a god. During his lifetime, in 44 bc Julius Caesar allowed a statue of himself to be erected with the inscription Deo Invicto (to the unconquered god) and declared himself dictator for life. His nephew and adopted son, Augustus (ruled 30 bc–ad 14), constructed a temple in Rome which he dedicated to Divus Julius (the divine Julius) and titled himself Divi filius (son of a god). Augustus and Tiberius each allowed a single temple to be dedicated to them during their lifetimes, the former in Pergamon and the latter in Zmyrna. Subsequent emperors gradually increased the influence of the Imperial Cult so that, after Hadrian (ruled ad 117–38), their power had become so absolute and so consolidated that the cult was effectively a civil religion and a test of loyalty. It was abolished by Constantine I (ruled ad 306–37), who adopted Christianity as the official religion.