Carolingian Consolidation
Very rare1.5%ObjectiveOptionalSingle-player
Starting as a Karling, be the only independent Karling to hold a landed title
Sounds like dynastic genocide; is actually a 1066 shortcut. Count Herbert of Vermandois is the ONLY landed Karling at that start, so the whole achievement reduces to "become independent". The reliable route: ally big names who'll join an independence war (William the Conqueror and Kaiser Heinrich are both willing), wait until they're at peace, declare, call them in, enforce demands. The wiki also documents a cheeky alternative: declare independence and surrender - if you're banished into landless adventuring, it can pop on the spot. Rated very hard by Paradox; from this start it isn't.