Complex sentence: When Olifard arrived in Scotland, he did so as a baron of the highest status, being the same level as the most favoured new comers into Scotland of the Anglo/Norman and Anglo/Flemish nobility.
Split into simpler sentences: When Olifard arrived in Scotland, he did so as a baron at the highest status. It was the same level as the most favoured new comers into Scotland of the Anglo/Norman and Anglo/Flemish nobility.