Mursili II was young and inexperienced, but he proved to be a strong king. In the first years of his reign he carried out punitive campaigns against several kingdoms. In Syria the Nuhashshi king Tette rebelled and was joined by Egyptian troops. Troubles in Syria continued when Mursili's brothers Tulipinu and Piyassili both died. The loss of his Syrian viceroys led to rebellion and even the invasion of Carchemish by Assyria. Leaving his generals to deal with Syria and Haysa, Mursili invaded Carchemish and drove out the Assyrians. Later in his reign Mursili II campaigned against the Kaska once again retaking the Hittite holy city of Niniveh. He also decisively defeating the King of Tummanna.