[1] When Kingsbury County School was opened in 1925, it was originally housed in a building which once belonged to the Aircraft Manufacturing Company, (or Airco as it was also known) on the Edgware Road opposite Colindale Avenue (now a Jewish school).

As the population of the surrounding area increased owing to the influx of workers to the aircraft industry, so did the roll of the school, and in 1929 a new school was built in Princes Avenue by John Laing and Co. at a cost of cost £43,638.

[1] The headmaster, Dr Payling (who had succeeded Mr Tracy after his retirement in 1949), saw the beginning of extensions in 1954.

The increase in the population of Kingsbury had continued unabated and building had started on a second mixed secondary school at a site in Bacon Lane in 1939 but this was not finished, mainly due to constraints placed in the continuation of the building by the Second World War.

[1] In 1967 with the local authority Brent Borough Council having adopted the comprehensive system of education, Kingsbury County Grammar and the two Tyler's Croft schools were amalgamated to form the giant Kingsbury High School.

Mr Mitchell served 18 years as Headmaster and was responsible for a series of important developments.

In Mr Mitchell's era, the ethnic makeup of Kingsbury began to change with the growth of a large Asian community.

After Mr Mitchell retired in 1988, the former head of neighbouring Preston Manor High School, Philip Snell, was appointed to succeed as Headmaster.

During the subsequent period the school's reputation from computing also began to grow and flourish.

This has been attributed largely to Mr Snell's interest in curricular advances and new information technology and the resultant building of the first computer-based Open Learning Centre in Princes Avenue with a special link for weather forecasting.