Alliance High School (or AHS) popularly known as “Bush”, was the first school in Kenya to offer secondary school education to Africans. It was founded on 1 March 1926 by the Alliance of Protestant Churches – The Church of Scotland Mission (later known as the Presbyterian Church of East Africa or PCEA), Church of the Province of Kenya (CPK), African Inland Church (AIC), and the Methodist Church.
The school is situated in Kikuyu, about 22 kilometers (12 miles) from Nairobi’s central business district. The school is a 10-minute walk from the Alliance Girls’ High School, its sister school.
It has always been ranked within the top ten best schools in each year’s National Examinations. It was ranked first in the country from 1960-85. In 1986 it lost its top ranking for the first time in 25 years, slipping to third. It was ranked first in the country in 2005 based on the results of the Kenya Certificate of Secondary Education(KCSE). In 2006 its rank dropped to third. In 2009 and 2010, the school emerged top in the KCSE results posting sterling performance. In 2011, the school dropped one place to second.