Son of the great Hittite conqueror Suppiluliumas, Mursilis succeeded his father after the brief reign of his older brother Arnuwandas III. Mursilis renewed the allegiance of North Syria, particularly Carchemish (controlled by his brother Shar-Kushukh) and the kingdom of Amurru; he also conducted a successful campaign against the western kingdom of Arzawa, one of the main threats to the Hittite realm. Chronic trouble with the Kaska in the north necessitated almost annual pacification operations (10 in all), and the region of Azzi-Hayasa (east of the Kaska) also had to be reconquered by Mursilis in a number of campaigns. A prolific personal annalist, Mursilis also edited an account of his father's exploits; his detailed descriptions of his own campaigns have yielded valuable information about Hittite military strategy.