As far as we can know, Avidius Cassius, a Roman senator and military man wanted to rebel against Emperor Marcus Aurelius, however he retired from this decision after having a vision of Jupiter himself (actually, Byzantine historian Procopius of Caesarea claims that vision was an effect of alcohol poisoning). What if he didn't see Jupiter and therefore rebelled against Marcus Aurelius, blocking Romans the road to conquest of Transdanubia? How would the world look like with much less presence of Romance-based languages? How would Celtic Britannia develop? How would Slavic development look like without Romance influence? I think that in the OTL Veneda, Marja and Slevania a new branch of Slavic languages would arise, called "Western Slavic"? Any names for ATL Slavic Veneds?