Sīrat Sayf ibn Dhī Yazan (Arabic: سيرة سيف بن ذي يزن, "The Biography of Sayf ibn Dhī Yazan") is a popular Arab romance dating to somewhere between the 15th and 16th centuries CE. A mixture of epic and pure fantasy, it is inspired by the life of Sayf ibn Dhī Yazan, a semi-legendary king of the pre-Islamic Himyarites (present-day Yemen) who reigned in the 6th century CE. He is known for defending Himyar against invasions from the Aksumite Empire (present-day Ethiopia), with the help of the Persian Sassanid Empire. The Sīrat Sayf ibn Dhī Yazan was produced in reaction to the Christian Crusades; it sought to portray the triumph of Islam indirectly, by recalling one historical defeat of the Aksumite Empire. (Although Himyar itself was pre-Islamic, the Aksumite Empire survived into the ninth century CE and opposed Muslim expansion into Abyssinia.) The story's principal antagonist is named "Sayf Ar'ed," which was also the throne name of Ethiopian emperor Newaya Krestos (r. 1344–1372), one of the leaders of the Negus in the war against the Muslim princes in the 14th and 15th centuries. The reference to this king is one of the elements that allow us to date the Sīrat as a late work. Source: Wikipedia (en)