The prison was opened as a county gaol in 1847 and served as such until 1890 when it became a women's prison. Two new wings were added in 1902 serving initially as an Inebriates Centre and in the 1930s as a girls' borstal. In 1959, the prison was converted to house adult male prisoners and in 1961, it changed again to house young male offenders aged between 17 and 21. In 1989, Aylesbury was designated as a long term young offender institution. Aylesbury holds the longest sentenced young adult males in the English prison system.