[eponeponepon]

Genghis Khan? Charlemagne, arguably..? Maybe one of the Qin emperors... yeah, there aren't many great military conquerors whose gains lasted.

Start digging in the arts and philosophy though, and there are plenty, after a fashion.

[riffraff]

Julius Caesar and Augustus? Those conquests lasted for a few centuries.

[pqs]

Napples and Sicily also have been part of the Spanish crown for centuries.

The Spanish kings held half of South America for centuries.

[Arnt]

Yes, South America is much bigger than Spain itself, was conquered quickly and then kept... good point. Thanks.

[Arnt]

Didn't Ghengis Khan's realm contract and then split when he died? IIRC Charlemagne gained two thrones (not by conquest), then added to that area by conquest, and largely kept the military gains.