The former church was destroyed by the Visigoths, at the end of 5th century, then by the Saracens in 725, the Normans in 848... In 1096, pope Urban II began the construction of a huge Romanesque Byzantine style church, which was dedicated to saint André and saint Jean, since they kept their relics in Bordeaux city.
The English seized control of the area in the middle of the 12th century; they extended the building until the 14th century.
But why did the English transform our cathedral? Because at that time, Aquitaine belonged to them!
Since the marriage of Eleanor of Aquitaine and Henri II Plantagenet in 1152... Henri became king of England two years later. An earthquake collapsed the vaults in 1427. The restoration was only finished in the 16th century.