March 1, 991: Peace between King Æthelred and Duke Richard of Normandy
With the benefit of hindsight and our knowledge of Duke William of Normandy's conquest of England in 1066, it would be easy to read too much into conflicts between England and Normandy in 991.
A letter from Pope John XV (c. 985-996) is our only surviving record of the conflict, noting that the Pope had many reports of the enmity and finally sent a legate, Leo of Trevi, with letters for both Æthelred and Richard. The rulers came to terms at Rouen on March 1, 991, and set out the peace in these terms: that if either of them, or their people, were to commit a crime against the other, it should be atoned for with fitting compensation, that the peace should remain between them forever unshaken, and that neither was to receive the enemies of the other.
The clause forbidding the harbouring of enemies might suggest that the Vikings had been using Normandy as a base for their raids against England in the 980s, just as they had raided across the channel in the ninth century. However, from the peace of 991 English/Norman relations grew stronger and stronger. Æthelred married Emma of Normandy in 1002, and when he was driven out of the country by the Vikings in 1013 he stayed in Normandy; some of his children, including the later King Edward the Confessor, grew up in exile at the Norman court. Indeed, it could be argued that the peace with Normandy would be much more dangerous in the long run...
Review the history, 991-1066.