In terms of its early history, the establishment of a Monastery in Malmesbury in about 686 AD was an event of paramount importance. Founded by Aldhelm, the Monastery consisted of three main churches. The first, at the heart of the Monastery, was dedicated to St. Peter and St. Paul. The second church was built to honour St. Mary, and survived until after the Norman Conquest, when it was replaced by the present 12th century Abbey. The third church was dedicated to St. Michael and is where Aldhelm himself was buried in 709 AD. It is unknown exactly when this church disappeared, but it may still have existed in the 16th century.
The building of the present Abbey began in about 1145 and its consecration service, and therefore the date when it was finished, is believed to have taken place in 1180. The layout chosen was typical of other major churches built in the 11th and 12th centuries, especially in France. What must have already been an impressive structure was further improved in the early 14th century, with works taking place over most of the next 100 years. As well as strengthening the overall structure, this is the stage during which the Abbey spire was constructed. After completion, it towered above the surrounding land, and was 30 feet taller than the Salisbury spire.
The 15th century saw the rebuilding of the Abbey cloisters, but unfortunately saw more degradation of the Abbey building. The most significant event was undoubtedly the collapse of the Abbey spire, which fell during a thunderstorm in the last quarter of the 15th century (the exact date is unknown). With the coming of the Reformation it seemed likely that the Abbey would be demolished, but the decision was made that it should be retained, at least in part. It was not until 1822-23 that any major refurbishment took place though, at which stage the Abbey acquired a new organ and a raised wooden floor for insulation. However, the Abbey was still in a sorry state of disrepair and the period from 1898-1928 was dominated by structural and interior restoration. Since then, sections of the Abbey have been extended with developments such as new lighting being introduced.
Bartholomew, Ron., A History of Malmesbury Abbey (The Friends of Malmesbury Abbey: Malmesbury, 2010).