How was Fridlevus II related to Halfdan?
Fridlevus II Fridleif (Ynglinga saga) was a son of Fróði of the Skjöldung (Scylding) lineage. In that work he was the brother of Halfdan and the father of Áli the Strong.
Haakon Paulsson Haakon Paulsson (Old Norse: Hákon Pálsson) was a Norwegian Jarl (1105–1123) and jointly ruled the Earldom of Orkney with his cousin Magnus Erlendsson.