 Viking fleets of over a hundred ships did occur, but these fleets usually only banded together for one single—and temporary—purpose, being composed of smaller fleets each led by its own chieftain, or of different Norse bands.This was most often seen in the Francia raids between 841 and 892.They can be attributed to the fact that it was during this time that the Frankish aristocracy began paying off Vikings and buying mercenaries in return for protection from Viking raids.