[mytailorisrich]

> Rollo the Walker was made ruler of the region by the king of France. This was allegedly after the vikings had tried to sack Paris for the n-th time. This deal was made on the premise that the people of Normandie would defend the rest of France from vikings and other raiders

The deal was also conditioned on religious conversion and allegiance to the King of France, and he also married the King's daughter.

Win-win.

[caporaltito]

Also, if you put a guy controlling Normandy, he will control the mouth of the river Seine which runs in Paris. So you secure the biggest city of your kingdom from being raided from this river by enemies rowing it upstream, which was the biggest problem with Vikings raiders back then.

[mytailorisrich]

I'm thinking the King thought Rollo was a massive pain in the ass but also a very capable guy so decided to kill two birds with one stone.

[eschulz]

Brilliant stroke of win-win diplomacy, so long as we keep the concerns of the daughter aside.