Gloucester Cathedral began life as the Abbey of St Peter, founded in 1089. Its exterior blends Norman Romanesque architecture — seen in the massive nave pillars and crypt — with later Gothic additions such as the soaring east end and 15th‑century tower. The most striking feature is the Great East Window: at 22 metres high and 12 metres wide, it is the size of a tennis court and was the largest window in the world when installed in the 1350s. Today this glass, along with the ornate Lady Chapel and King Edward II’s tomb, makes Gloucester Cathedral a highlight of English medieval architecture and a popular backdrop for films and TV. Although the Harry Potter production used the cloisters for Hogwarts’ corridors, the exterior itself appears mainly in establishing shots, lending its ancient towers and buttresses to the wizarding world’s atmosphere.