The player may also compete for the title of King of Pendor, but if he does so, he will have to beat all 5 kingdoms, instead of 4 with the help of the one he joined. Upon capturing your first fief as a freelancer, you will take it for yourself, starting your own kingdom.
Talk to your minister (you should try to assign this role to your wife (if any), else a companion) for the first time so that he welcomes you and asks which culture will the kingdom be based on. The player will be able to choose between the 5 existing kingdoms' cultures, or the Pendor culture. After this, he will ask you to select a crowned helmet of the 11 possible ones (the 5 of the other monarchs, the 5 from the claimants, or the helmet of Pendor. Here are their names and models:
Note: you will always get 2 Royal Crowns (one is meant for your spouse) + the helm you decide. All helms have the same stats (60 head armor, 6 body armor) except for the Royal Crown (24 head armor)
Your next step is to hire a Mercenary Company that will support you out defending your new kingdom mainly against the kingdom you took it from, as they will attempt to reconquer it. You should make some companions into lords, giving these the villages your walled fief (castle/city) has, so that they can start gathering an army as soon as possible. Make sure to appoint companions that are nobles with either good natured or upstanding personalities (in particular Sir Roland); this will make it immensely easier on yourself. Tell your steward to start training troops to raise the garrison that will be helpful to restock your army and for the initial siege defense. Don't go too far because if the enemy lords may rush the siege, and they will chase you if you try to enter your fief.
When you successfully defend against the siege, you will now be able to expand and absorb the other kingdom, as it'll be weakened by that failed siege. How you handle the rest of the game is up to you!