Qur’anic verses define as heirs several classes of kin that were previously unable to inherit – most notably women such as wives, daughters, mothers and sisters – and distributed the estate in an equitable way that was a drastic improvement from the pre-Islamic scheme. The Qur’an specifies three main classes of heirs: (1) the Qur’anic heirs called “Sharers,” (2) agnatic heirs called “Residuaries,” and (3) uterine heirs called “Distant Kindred.” Not all possible heirs always inherit; some classes may exclude others, and some heirs within a class may exclude others within the same class.