Although some believe that Bristol was formed during the rule of the Romans, documentation shows that there were only settlements in surrounding areas. Sometime in the 10th Century, coins were minted in the city and a castle was erected. This is known because in 1068 the sons of the dead king tried to attack the city, but were soon driven off. In September of 1118, an earthquake destroyed most of the city. Even though this was disastrous at the time, there have only been a few earthquakes throughout the city's long history. At other times, the city has been devastated by flood, famine, and fire. St. Augustine's Abbey was founded in the 12th Century, and soon after that the fortifications in and around the city were bolstered and improved. Because of this, the city itself grew considerably. Many political prisoners ended up being held captive in the newer castle. As time went on Bristol became more and more important in domestic and foreign travel. The amount of commercial trade in the city was enormous, and with that brought both success and large numbers of inhabitants to the city. During the English Civil War, Bristol was on the side of Parliament. Royalists ended up capturing the city, but two years later power was restored. Oliver Cromwell ordered Bristol Castle to be destroyed to the pleasure of many citizens. Eventually growth of the city moved beyond the walls, and many medieval villages, eg Montpelier, Westbury-on-Trym and other suburbs such as Clifton became part of the City of Bristol.  Bristol is unique in that it was a County about 200 hundred before its City status, and then became both a County and City in its own right; for some time became part of Gloucestershire, then the south straddled Somerset and was later part of Avon, but has returned to its former independent status.