Marcus Arrecinus Clemens (fl 1st century), was a prefect of the Roman imperial bodyguard, known as the Praetorian Guard. Clemens came from obscure origins and according to the historian Suetonius, his family were of Equestrian rank. He was the namesake of his father. Clemens' mother could have been named Julia and his sister was Arrecina Tertulla, who became the first wife of the future Emperor Titus. There is a possibility that Clemens was related to the paternal side of Vespasian. Vespasian's paternal grandmother bore the cognomen Tertulla and this cognomen was also borne by his sister and paternal grandmother.[citation needed] Clemens served as prefect in the early reign of Emperor Vespasian, from 70 until 71. Clemens acceded to this position by appointment of Vespasian's political ally