The post-Roman development of St Albans was in memorial of Saint Alban, who tradition states was executed in 209 - the earliest known British Christian martyr. There was a shrine on the site of his death and in the 400s a monastic church was constructed. Another abbey was founded by King Offa of Mercia in 793. The settlement grew up around the precincts of another monastery, founded in AD 900 by Abbot Ulsinus, he also founded three churches - St. Peter's, St. Stephen's and St. Michael's. Around 500 people lived in the town in 1086.
The cathedral was started in 1077 by Paul de Caen, the 14th Abbot, it was completed in 1089 and was 350 feet long with a tower and seven apses. The head of the abbey was confirmed as the premier abbot in England in 1154. The abbey was extended by John de Cella in the 1190s, and again between 1257 and 1320 but financial constraints limited the effectiveness of these later additions. A convent was founded nearby in 1140.
The Abbey came into increasing conflict with the people of the town of St Albans, who demanded rights of their own. This led among other things to the construction of a large wall and gate surrounding the Abbey and the construction of the "clock tower" in the town. St Albans played a role in the Peasants Revolt of 1381, presenting a charter for the freedom of St. Albans to the Abbot on 16th June 1381, in which various rights were demanded.
During the Wars of the Roses there were two battles around St Albans. The first Battle of St Albans in 1455 was a Lancastrian defeat that opened the war. The Lancastrian army occupied the town but the Yorkist forces broke in and a battle took place in the town centre. In 1461 the Second Battle of St Albans on Bernards Heath on the north of the town resulted in a Lancastrian victory.
Following the Reformation, the Abbey was dissolved in 1539 and sold to the town in 1555. In May 1553, in response to a public petition, the first royal charter for the town was issued by King Edward VI, granting it the status of a borough. The charter defined the powers of the major and councillors, then known as burgesses, as well as specifying the Wednesday and Saturday market days. The Abbey became a protestant parish church for the borough.
During the English Civil War (1642-45) the town sided with parliament but was largely unaffected by the conflict.
The railway arrived in 1868, off-setting the decline in coaches since the 1840s - St Albans was a major stop on the route north out of London, this is the reason it has so many pubs.
In 1877, in response to a public petition, Queen Victoria issued the second royal charter, which granted city status to the borough and cathedral status to the former abbey. Lord Grimthorpe financed a £130,000 renovation and rebuilding of the then delapidated cathedral, which is most apparent in the generally poorly regarded Victorian rebuild of the west front.
The football club was founded in 1880.
There are three main roads dating from medieval times - Holywell Hill, St Peters Street, and Fishpool Street. These remained the only major streets until around 1800 when London Road was constructed, to be followed by Hatfield Road in 1824 and Verulam Road in 1826. Growth was always slow and steady, there was no sudden burst - in 1801 there were 6,000 people living in St Albans, in 1850 11,000, in 1931 29,000 and in 1950 44,000.
A market was running outside the abbey from the 10th Century, it was confirmed by King John in 1202 and by a Royal Charter of Edward VI in 1553.