Yes: If you use the leave kingdom button in the clan menu you will break of from the faction and have the option to keep all your fiefs (starting war with old faction) or leave your fiefs. If you talk to your ruler you only have the option to leave without fiefs.
TIP: DO NOT use the make kingdom button right away. Once you MAKE KINGDOM you can be attacked by any faction and are subjected to the influence system. Instead, stay as an independent clan with you fiefs in tact. In this state nobody can declare war on you and you can start wars (attack lords) without dealing with the influence system. So you can make peace, recover, attack, take a fief, make peace, recover and so on. Do this until you've carved out a good home and built up relations (and money) with lords via beating them and releasing them. Really milk this stage and don't create kingdom until you've done every other type of thing you might want to, because once you're a kingdom you will likely always be at war.
Save up 100k before you leave faction though in case you need to pay for peace.