(Preface: I know basically nothing about medieval history and the geographical distribution of lions, forgive any dumb stuff I say lol)
From what I can tell, lions are animals native to sub-Saharan Africa. Why were they so prevalent in Europe? Like, you have the three on the Royal Arms of England, one on the Royal Banner of Scotland, one on the Coat of Arms of Finland, and even Richard I of England was called "the Lionheart". I get that the Romans brought them up to fight gladiators but did that really influence later medieval culture so much?
Again, forgive my ignorance, I'm just really curious as to why an African animal would be so important to the heraldry and culture of medieval Europe.
Here is an amazing answer by u/jschooltiger which itself contains links to other older answers
There was a comment, which got removed, that was slightly hostile as to why there is not a proper answer to leonine questions, like this one, which we often see on other topics. So, basically, this will be a negative and slightly meta answer to those reasons, why leonine studies are hard to come by, interdisciplinary, and quite impossible to pin down due to the omnipresence of leonine iconography and symbolism across ( almost all ) European and Near Eastern societies, so definitively tracing back and establishing a firm line of connection is probably impossible, then one has to argue and establish not only the transmittance of a motif, but meaning as well.
Since there is not ( to my knowledge ) a thorough and systematic study of leonine iconography, one has to look through fragmeneted art historians, like Émile Mâle, Michael Camille, Martin Blindheim, Elisabeth Sears, for roughly medieval setting, and John Boardman, John Carter, Hölscher F. and so forth for classical period, with significant differences between them. But then one has to find culture-specific studies to be thorough, as leonine art and symbolism can be found in Anglo-Saxon, Norman, Islamic, Viking, Roman, and while some generalities can probably be said about them, an Anglo-Saxon funerary practice with leonine motif will still nontheless differ substantially than Islamic depictions. ( Which were also very influential for Medieval Europe, specially with textile trade ).
With all those difficulties already named, there is more, and on this point, like with others, there is certainly plenty of disagreement, namely, symbolism or decoration, how to seperate the two, are they always mutual and inseperable, but if so, how to account for so many divergent functions of leonine decorations, such as;
- Royal
- Guardianship and support
- Loyalty and lion ( St. Jerome, oodles of Medieval literature )
- Defeat
- Human triumph ( with assistance ) ( Classical and Hebrew tradition, Heracles, Samson, David et all )
- Leo constellation and zodiac
- Godhead lion
- and lion in the Bible ( which is another issue, a legion of them / St. Mark )
- Lion as animal of Ressurection
- Punitive and ferocious lion
- Mercy and lion
- Funerary practices and lion
etc.
Each of these functions will differ across cultures, some will have them, so will not, perhaps they share genealogy, perhaps not.
Then there is another equally broad topic to look at, namely, trade, and the transmission of motifs on art and textile trade, then there is literature, with equal abundance, and what role it played in symbolic and decorative art.
With such questions, if one is not precisely specific ( time, place, function ), it is indeed hard to address them, and then there has to be a study on this specific thing.
Hopefully that clarifies the matter a bit.