Canterbury as a city has it's origins in the Roman settlement of Durovernum Cantiacorum, established in the first century AD after the Roman invasion of 43 AD. The name was taken from the Cantiaci tribe that inhabited the area at the time of the Roman invasion. The name of the county of Kent also derives from them. Durovernum Cantiacorum was abandoned following the Roman withdrawal from Britain around 407 AD. Little remains of Roman Canterbury now but the "Roman Pavement" mosaic can be seen in the city's Roman Museum, and a Roman hypocaust (ancient heating system) is on public view in the basement of the St Margaret's Street branch of Waterstones bookshop.

The city was resettled by the Anglo-Saxons known as the Jutes, and as Cantwaraburh it became the main settlement of the Jutish kingdom of Kent. In 597 the Pope sent an expedition from Rome to convert the Anglo-Saxon people to Christianity. The leader of this expedition, Augustine, was welcomed by King Æthelbert (who already had a Christian wife, Queen Bertha) and was allowed to found the cathedral and abbey, becoming the first Archbishop of Canterbury. Canterbury was therefore established as the first 'English' site of Christianity. The position of Archbishop of Canterbury remains the head of the English church and Canterbury Cathedral remains the 'mother church' of England. The remains of St Augustine's Abbey contain the burial places of St Augustine and the early Kentish kings. Modern statues of King Æthelbert and Queen Bertha can be seen in Lady Wooton's Green.

 Betha - Queen of Kent

Following the Norman Conquest in 1066 the Cathedral and Abbey were rebuilt in stone along with a stone castle and city walls. After the martyrdom of Archbishop Thomas a Becket inside the cathedral in 1170, Canterbury became a major European centre of pilgrimage, as documented in Chaucer's medieval stories The Canterbury Tales. There were several buildings to house pilgrims such as the Eastbridge Hospital which can still be visited today. King Henry VIII's split with Rome to form the Church of England led to the destruction of Beckett's shrine and also St Augustine's Abbey during the dissolution of the monasteries. The abbey is in ruins today.

In the 17th century the city expanded in population with an influx of protestant Hugenot refugees from French-speaking areas of Belgium which established Canterbury as a leading city in the weaving industry. The Old Weavers House of 1507 still stands in the city centre. In the 18th century the castle and much of the city wall became ruined and all but one of the medieval city gates were demolished for road-widening. The Westgate remains intact and is the largest city gate in England. About half of the medieval city wall remains though in some parts has been heavily reconstructed. Most of the 'old' buildings left standing in Canterbury date from the 16th-19th centuries.

The city suffered considerable destruction during the Second World War largely on the raid of 1st June 1942. St George's Street and the area now containing the Whitefriars shopping centre (about one quarter of the old city) were almost completely destroyed. Importantly, the cathedral survived. Unlike in many parts of Europe, but as elsewhere in Britain, a decision was made not to reconstruct the historic market-town appearance but to construct a modern city in it's place. Several buildings that remained partially intact such as St George's Church were cleared during the 1950s to allow for streets to be widened and straightened. Only the clocktower of the church was left and St George's Street has only one other remaining pre-war building (Marks & Spencer's shopfront). The construction of the ring-road in the 1960s led to further demolition of buildings outside the city wall and the filling in of the old defensive moat. But together with a city by-pass built in the 1970s this allowed the city centre to be pedestrianised (until then traffic from London-Dover went through the old city centre). Much of the unloved 1950s-60s construction has largely been redeveloped yet again since the late 1990s and fortunately much of the historic pre-war city remains largely intact to be enjoyed today and the modern quarter has enabled Canterbury to flourish into a thriving centre for shopping and eating. Canterbury now has a buzzing cosmopolitan atmosphere with large numbers of tourists, shoppers and students (both from its universities and the many international language schools) giving it an extremely vibrant feel for a city of a relatively small size (population about 45,000).