system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do lions appear on old european heraldry despite lions not existing in Europe ?
gpt
1) Lions lived in parts of Southern and Eastern Europe until the 300s AD. So in many regions there was cultural memory of the beasts even if they died out several generations previously. 

2) The Romans took their gladiatorial fighting traditions wherever they conquered and a major part of that was importing exotic animals for people to fight. So lions would be known in Romanized Europe. 

3) They had trade routes to the Middle East and to Africa which would allow for the wealthy Nobles and Royalty to import exotic animals for menageries which were popular in the middle ages.