The Roman emperor was the ruler of the Roman State during the imperial period (starting in 27 BC). The emperors used a variety of different titles throughout history. Often when a given Roman is described as becoming "emperor" in English, it reflects his taking of the title augustus or caesar. Another title often used was imperator, originally a military honorific. Early Emperors also used the title princeps. Emperors frequently amassed Republican titles, notably princeps Senatus, consul and Pontifex Maximus.