Difficulty: MediumThe fastest way to adopt Feudalism is to use the "Adopt Feudal Ways through Liege" decision. Conquer land in Poland until you are stronger than the ruler of Great Moravia. Then border Great Moravia and convert to Catholicism, so the leader will want to take you as a vassal. Swear fealty to Great Moravia and take the decision to become feudal. At this point, either fight for independence to form Poland or take over Great Moravia from within. Either way, make sure you own and keep the Kingdom of Poland.
The artifacts can be acquired by sponsoring their creation yourself, and by taking them from others. To get more Inspired characters, raise court grandeur, switch to a Scholarly court, and get the first Erudition dynasty legacy. Periodically use the character finder to search for characters with inventory artifacts, sorting by rank, and focusing on emperors and kings. With the Accomplished Forger perk, buy claims on their artifacts, then demand the artifacts, steal them or go to war for them.
Credit to
Bayek von Kuwaq on Steam for his
guide.