I scoured the CtL book for examples but couldn't find any. If there are any I'd love a page number. Otherwise, if you have a link to a wiki with them I'd appreciate that as well.
The pledge you are looking for is called Commendation and is found on page 189 of the core Changeling book.
Page 181 of the Changeling core book has the Vassalage boon and a side panel that explains that freeholds come in many shapes and sizes but the ones that are enforced by the Wyrd are usually pledges of loyalty sworn to an anointed ruler.
If you are interested in an example of one that is in play after many revisions and years of play, feel free to look at the one for a game that I'm a part of.