Kath (Khwarazm)

Kath was the old capital of the region of Khwarazm, on the right bank of the Oxus (Amu Darya) in present-day Uzbekistan, before the seat of power shifted to Gurganj. The polymath al-Biruni (d. c. 1050) was born in or near Kath; the mathematician al-Khwarizmi (9th c.), from whose name 'algorithm' derives, took his nisba from Khwarazm.