Munch suggested that Haakon III's mother could have been Astrid Roesdatter, daughter of Bishop Roe in the Faroe Islands, but this has not been supported by later historians.
The background for these conflicts were the unclear Norwegian succession laws, social conditions and the struggle between different aristocratic parties and between Church and King.
The same spring the Norwegian bishops, who had been in exile in Sweden and Denmark and had supported the Bagler, returned to Norway and made a settlement with Håkon.
A new Bagler pretender, Erling Steinvegg, soon appeared in Denmark, but declined to renew the fighting, as he saw little chance of succeeding against Håkon.
In the end she had one of her men undergo a trial by ordeal on her behalf to prove her innocence, but the man was badly burned.
In the summer of 1218, Inga underwent a successful trial by ordeal (bore iron) in Bergen to show the paternity of her son.
During Håkon's brief reign, he managed to release Norway from the church's interdict, and end the civil wars, at least for a time.
As it turned out, his early death sparked a renewal of the fighting, as the bagler pretender Erling Steinvegg in a matter of months gathered an army and went to Norway to claim the throne.