sentences:  Nippur, the formerly great city, which had been virtually abandoned c. 1730 BC, was rebuilt in the Kassite period, with temples meticulously re-built on their old foundations.In fact, under the Kassite government, the governor of Nippur, who took the Sumerian-derived title of "Guennakku", ruled as a sort of secondary and lesser king.The prestige of Nippur was enough for a series of 13th-century BC Kassite kings to reassume the title 'governor of Nippur' for themselves.