The city takes its name from Alban, the first British saint who lived in Verulamium during the 3rd or 4th century. He converted to Christianity after sheltering a fleeing priest and was executed for refusing to renounce his faith.
Roman occupation ended between 400 and 450 AD after the town had grown significantly following its elevation to a municipium around AD 50. Archaeologists dated a black ash layer to 60, 65 AD confirming destruction by Boudica of the Iceni in 61.
Ulsinus founded the Benedictine Abbey of St Albans in 793 on a hill east of Wæclingacaester before construction began in 1077. The abbey dissolved in 1539 and later became a cathedral in 1877.
City status transferred district-wide via letters patent dated the 9th of July 1974 after Queen Victoria issued a second royal charter granting city status in 1877. The borough was abolished on the 1st of April 1974 becoming part of larger St Albans City and District.
The First Battle took place inside the town on the 22nd of May 1455 while the Second Battle occurred just north on the 17th of February 1461. These conflicts were significant events during the Wars of the Roses era.