The Timeline of the Series Is Messed Up
In the series, Ragnar is depicted as a man in his mid-late twenties. He is portrayed as the leader of the raid on Lindisfarne, an island off the northern coast of England. Ragnar Lothbrok, the historical figure, happened to invade this island 50 years later. Therefore, he would have to be an elderly man in his seventies, because it was in the 840’s that he and his Viking fleet invaded and sacked Paris. Taking the historical period into consideration, it is highly unlikely that he was 90 years old when he died in Northumbria. Except in rare cases, no man lived that long 1000 years ago.