The County of Dassel (German: Grafschaft Dassel) emerged shortly after the turn of the 11th and 12th centuries when, after the extinction of the male line of the Billungs, its seat in Suilbergau, north of the Solling hills was divided into the domains of Einbeck and Dassel. Reinold of Dassel was able to secure rights similar to comital rights. The county lasted about 200 years, till it was abandoned in 1310 when there were no heirs. The most prominent member of the comital family was Rainald of Dassel, chancellor to Emperor Frederick Barbarossa and Archbishop of Cologne.