Kammala jumla mai zuwa: Roos shi ne ɗan fari na Robert Roos, Ubangijin Moor End da Anne Halsham. Lokacin da mahaifinsa ya mutu a 1448, Henry ya yi nasara a matsayin mai kula da gandun daji na Rockingham. An nada Henry a matsayin Constable na Roxburgh Castle, Scotland a cikin 1458 har zuwa 1460. Ya yi yaƙi a gefen Henry VI da Gidan Lancaster a lokacin Yaƙin Wakefield (30 ga Disamba 1460), a Gicciye na Mortimer (2 ga Fabrairu 1461), a Yaƙin Na Biyu na St Albans (17 ga Fabrairu 1461) da Yaƙin Towton (29 ga Maris 1461). Ya gudu zuwa Scotland bayan yakin Towton, tare da Margaret na Anjou kuma ya yi tafiya tare da Margaret zuwa Faransa. Henry kuma ya yi yaƙi a
Yaƙin Tewkesbury a ranar 4 ga Mayu 1471 inda aka ci sojojin Lancaster da ya nemi mafaka a Tewkesbury Abbey bayan yaƙin. An gafarta masa daga baya kuma an nada shi Sheriff na Sussex & Surrey a 1477 da 1483. A shekara ta 1491, Henry ya kasance dan majalisa na Sussex.