He was born in the outer district of Kath, the capital of the Afrighid dynasty of Khwarezm[7] (or Chorasmia).[8] The word Biruni means from the outer-district in Persian, and so this became his nisba: al-B??r??n?? = the Birunian.[8] His first twenty-five years were spent in Khwarezm where he studied Islamic jurisprudence, theology, grammar, mathematics, astronomy, medics and other sciences.[