How do you give your setting a sense of history besides "moar

I would say art and architecture is a good way to do it. It's easy to tell which cities and cultures are the oldest because they usually have the grandest architecture and widest array of fine art. It's basically just well preserved ruins.

So my players were interacting with an empire whose ruler had been upon the throne for some 900 years. The empire was of the style of one in the later stages of collapse, witch previous colonies declaring independence. Basically display past glory and the loss of glory is probably the biggest thing I can think of.

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Imperial remnants.

>>53421636
I like the idea of a generational game where part of it takes place in the past version of a setting and the next game takes place in the modern setting perhaps shaped by their old charaters.

Ethnic groups descendants from mixing populations of the locals and the long gone empire.

Artificial race created to serve a kingdom that no longer exists and have been searching for a purpose.

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>>53421636
I find an easy trick is to use recurring symbols/banners/crests. Have them show up enough, and players will start to wonder at the significance behind them. Slight changes over long periods of time or changes based on area can imply at deeper lore as well.

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>>53421636
If you're willing to put in the time and effort, create a Google Document to serve as a sort of "codex", and then whenever a player visits a new area or encounters an important NPC or finds an important artifact, ect. write something on the codex document explaining a bit of what the thing is and what's it's past is. If you've got good players, they'll read it in their own time between sessions, if you make it available online or otherwise easily accessible.

>>53421636
Old grudges. One princedom and its neighbor have been at each others' throats for ninety years and show no signs of stopping, etc.

>>53421636
Festivals and holidays. They let the history feel alive in the way it currently affects the setting. There don't need to be infodumps unless the players are interested. If they're not, they can take part in the related festivities!

A few ideas:
A festival commemorating the nation's victory in a culturally important war. Holiday for the birth of an important religious figure. New year celebrations.

>>53422450
You're making me nostalgic for the holiday/celebration-themed 3rd party books I had for D&D. There was some great stuff in there like rules for festival games and little holiday trinkets.

>>53422493
Those sound great! What happened to your books? Do you remember the name?

Language, mutated cultural customs, recurring motifs/patterns, complex population distribution

Basically, give it an actual history and use the natural products of that