Start as a Norse OPM in 769. When you gather enough gold from raiding, invade Wallachia area. Convert to Vlach and Catholicism and then eliminate the Byzantine Empire and Create a Vlach Latin Empire.
True Rum Kaiseri
Description: Found Roman Empire as Christian Turk.
Requirement: Start as Moghis Seljuk(Orthodox Seljuk guy in 1220s) and found Roman Empire.
Romanian Empire
Description: Found Roman Empire as true descendants of Romans.
Requirement: Start as a Vlach ruler(only possible after 1300) and found Roman Empire.
Pirates who?
Description: Conquer all Germanic rulers before they start raiding.
Requirement: No germanic ruler exists and Viking age event hasn't happen
You do not decide ;DI would like to say thanks for all suggestions submitted so far. I've enjoyed reading them As for what challenge I'll choose.. I find the idea of staying as a vassal throughout the whole game, but I'll wait for a day or two for more suggestions
¨Start as a powerless norse/suomi/slavic count (without prestige). Raid or wait until you have enough money and prestige to start an invasion.
Invade Mauretania or Africa
Convert to zoroastrianism
Go full inbreeding when you can (no allies)
Conquer some stuff
Reclaim Persia and become Shaoshyant
Reform SPQR and convert to the Aztecs faith and reform it.
As a Jain count, convert to Germanic paganism and make it dominant religion in India.
As a Catholic ruler of the HRE, convert the HRE to a heresy in its entirety, and fight both aztecs and Mongols....and win.
You do not decide ;D