It was founded in the 7th century , reorganised in the 10th century , and rebuilt in the 12th and 16th centuries . It is one of the finest and largest examples of Gothic architecture ( Perpendicular style ) in the West of England . Founded in the 7th century , reorganised in the 10th century and rebuilt in the 12th and 16th centuries , it is one of the largest examples of Perpendicular Gothic architecture in the West Country .