According to Ibn Ishaq, the king of Himyar named Dhu Nuwas had burned the Christians in Najran, and an invading army from Aksum (Habashah) occupied Yemen.
According to the Arab historians, Dhū Nuwās then proceeded to write a letter to the Lakhmid king Al-Mundhir III ibn al-Nu'man of al-Ḥīrah and King Kavadh I of Persia, informing them of his deed and encouraging them to do likewise to the Christians under their dominion.