Based on the interest in Settlers, I'd strongly recommend The Total War series. It checks all of the boxes:
- History
- Economy and resource management
- Negotiation
- Strategy
- ATTACK!
There are different versions of the game reflecting different historical periods. The battle simulation engine is AWESOME, and the units and tactics are well representative of the respective time periods and individual national characters. All of the units move simultaneously, and the user can only pause or accelerate the passage of time, so battles are quite demanding on executive function.
A favorite for me is Empire: Total War, which reflects the 1700s across three theaters (Americas, Europe/North Africa/Near East, India), and includes a campaign that simulates the American Revolution. This title has been around for a few years now, and can be found on the cheap.
