I saw this comparison of CK2 and EU4's political maps on the forum

Crusader Kings II is 5 years old this month

Europa Universalis

Can you spot all differences in the UI and map? Early 2014 : r/eu4

Europa Universalis 4 - #3756 by Mark_Weston - Games - Quarter To Three Forums

Giant in the Playground Forums

Crusader Kings II: The Seven Kingdoms mod - ModDB

Europa Universalis

Discovery: Dutch geography is far from correct in CK3. A CK3 Map/Google Maps comparison : r/CrusaderKings

Let's rewrite history: Underdog EU4 Multiplayer - The Something Awful Forums

Giant in the Playground Forums

Steam Workshop::CK2-Like Maps

Europa Universalis IV - Gaming - WoTLabs Forum