https://www.bbc.com/news/uk-england-humber-69051462
It’s amazing that ancient artefacts are still being found worldwide to this day. I highly doubt that Oysters played a part in the decision to go to Britain, more likely it was land to be conquered and a logical decision was made. World domination has always been the goal of powerful empires and still is today.
Obviously there would be commercial interests in any nation to exploit and Britain had plenty resources to exploit including its people.