... I didn't use a petition because I haven't lost anything, but I think there's a bug in the sovereignty claim option. The information under sovereignty says you have to research sovereignty, serfs, and landholding, then send an occupying army, and click on "claim sovereignty". I did all that, and got a message saying that to claim sovereignty you must research : at least "both" serfs, landholding, and socage. The word "both" in there gave me pause .. anyway, I posted in alliance chat what was happening, and someone else said he thought it was a bug - the same thing had happened to him. I tend to agree, since socage is the ability to claim sovereignty on TWENTY squares! That, combined with the instructions that you need to research "sovereignty, serfs, and land-holding" make me think that this might be a bug, too, so I wondered if anyone had ever reported it.