Board Thread:General Discussion/@comment-50.72.49.241-20130930130812/@comment-993964-20170509133634

144.167.243.205 wrote: "The Ash-King, having fulfilled his promise, returned to Sovngarde. Jorunn was crowned High-King of Skyrim three weeks later at the Palace of the Kings in Windhelm, though not without contention. His twin brother, Fildgor Strong-Prince, who led the Stormfist Brigade during the invasion, sought to take the throne by force. Jorunn succeeded in exiling his brother and ushered an era of peace and diplomacy across Skyrim and the newly-formed Ebonheart Pact. Jorunn also had a son, Irnskar."

So, according to this, that lovely Nord tradition that Jarl Stormcloak tried to uphold wouldn't involve murdering your fellow man. You don't have to murder your opponent if supposedly they yield but it's still a duel that can end in death. Kjoric the White killed Asurn Ice-Breaker in a duel for the throne. Accepting the challenge also accepts the judgement of the victor, and as a better candidate for high king, they can sentence you to death.