When The Settlers III was released, 1024x768 was a standard high resolution. Modern monitors often run at 1920x1080 (1080p), 2560x1440 (1440p), or 3840x2160 (4K).
Features modernized multiplayer through Ubisoft Connect. How to Configure It settlers 3 widescreen
For most of the 2010s, the consensus on forums like Siedler-Community.net and Reddit was grim: “Play it in a window. The engine is baked.” When The Settlers III was released, 1024x768 was
Toggle or Keep Aspect Ratio if you want to eliminate black bars. In the Video tab: When The Settlers III was released