The system of "feme sole" and "feme covert" developed in England in the High and Late Middle Ages as part of the common law system, which had its origins in the legal reforms of Henry II and other medieval English kings. Medieval legal treatises, such as that famously known as Bracton, described the nature of coverture and its impact on married women's legal actions. Bracton states that husband and wife were a single person, being one flesh and one blood, a principle known as 'unity of person'. Husbands also wielded power over their wives, being their rulers and custodians of their property.