The Ugarit correspondence at the time mentions invasions by tribes of such as the mysterious Sea Peoples. Equally, the last Linear B documents in the Aegean (dating to just before the collapse) reported a large rise in piracy, slave raiding and other attacks, particularly around Anatolia. Later fortresses along the Libyan coast, constructed and maintained by the Egyptians after the reign of Ramesses II, were built to reduce raiding.