In the 9th century, the abbey was raided twice by Vikings, which made the monks flee to Laon.
After an absence of nearly 50 years, they came back to Ghent and re-established the abbey.
The German emperor Otto II saw the abbey as a strategic defense point on the Scheldt river (the former border between the Holy Roman Empire and West Francia) in his eternal conflict with Louis V of France.
Saint Bavo Church in Aardenburg, Netherlands, was founded by monks of the abbey in 959.
[3] A coercion castle, with its cannons directed at Ghent, was built on the location of the abbey.