Having espoused the cause of Arthur I, Duke of Brittany, he was captured at Mirebeau (1202), and imprisoned in Corfe Castle although he is reputed to have escaped by making his jailers drunk and overpowering them.

Philip II of France bought his services in 1212 and gave him command of a fleet which was destroyed in the Flemish port of Damme.

He was one of those whom John designated on his deathbed for a council of regency to govern the Kingdom of England in the name of new king Henry III (1216).

In the late Autumn of 1218, Savari probably helped Alfonso IX of León in his ill-fated attempt to capture the Almohad controlled city of Cáceres, Spain.

He defended Saintonge against Louis VIII in 1224, but was accused of having given La Rochelle up to the king of France, and the suspicions of the English again threw him back upon the French.