Jayek is a village directly to the north of Javiksholm, the capital of the Fierdsvain. It is originally owned by Jarl Olaf Oakenshield. If you start in Javiksholm, it is a good place to start your warband. Because of its location, you can easily recruit Fierdsvain Recruits to join your party. Just be careful of the rediculous amount of Vanskerry that spawn between there and Tebandra.
If you succesfully capture Javiksholm, Jayek will join your kingdom.