The imperial county of Holstein-Kiel was a line of the House of Schauenburg and Holstein from 1261 to 1390.
When he retired, his sons John I and Gerhard I ruled jointly in Holstein.
When Adolphus V died in 1308 without a male heir, Holstein-Segeberg returned to Holstein-Kiel.
After the death of Count Gerhard V of Holstein-Plön, a nephew of John III, the Plön main line ended in 1350 and so John III took over the County of Holstein-Plön.
When Adolphus VII died without heirs in 1390, Holstein-Kiel and Holstein-Plön went into the hands of Count Gerhard VI of Holstein-Rendsburg.