The county Holstein Segeberg was from 1273 to 1308 a county in Holstein and a line of the noble family of Schauenburg and Holstein. The only Count of Holstein- Segeberg was Adolf V. ( the Pommerer, * 1252, † 1308).
After the death of his father Johann I ( 1263 ) whose sons Adolf V., Johann Albrecht II and ruled I. († 1300), the provost of Hamburg, was first together the county Holstein Kiel. In 1273 they shared the heritage, with John II continued to Kiel reigned. Adolf V. reigned Segeberg and so founded the line of Holstein - Segeberg. When he died in 1308 without a male heir, Holstein Segeberg fell back to Holstein Kiel. Adolf ( * 1281, † 1315 stabbed ), the younger son of Count John II, reigned 1308-15 in Holstein Segeberg.