Kiambu County is a county in the former Central Province of Kenya. Its capital is Kiambu and its largest town is Thika. The county is adjacent to the northern border of Nairobi County and has a population of 1,623,282.Its governor is William Kabogo. The county is predominantly rural, but its urban population is increasing as Nairobi is growing rapidly. Kikuyu are the dominant tribe in the county.In 2007, Kiambu District was subdivided in two: Kiambu East and Kiambu West.