Theo van den Hout, Professor of Hittitology and Editory of the Chicago Hittite Dictionary, has published an overview of the Hittite empire.
Theo P. J. van den Hout. "A Short History of the Hittite Kingdom and Empire." In Meltem Doğan-Alparslan and Metin Alparslan (eds.). Hittites: An Anatolian Empire. Istanbul: Yapi Kredi Yayinlari, 2013, 22-45.