In 164 BC, Rhodes signed a treaty with Rome, and the islands became aligned to greater or lesser extent with the Roman Republic while mostly maintaining their autonomy. Rhodes quickly became a major schooling center for Roman noble families, and, as the islands (and particularly Rhodes) were important allies of Rome, they enjoyed numerous privileges and generally friendly relations. These were eventually lost in 42 BC, in the turmoil following the assassination of Julius Caesar in 44 BC, after which Cassius invaded and sacked the islands. Thereafter, they became part of the Roman Empire proper. Titus made Rhodes capital of the "Provincia Insularum", and eventually the islands were joined with Crete as part of the 18th Province of the Roman Empire.