Baseline (Widescreen) Solution & Issues
Native. Empire Total War has two main gameplay modes, the campaign map and the battle mode. Each is Hor+ on all widescreen resolutions.
Empire Total War's menus are Hor+ through 16:9, then are pillarboxed with static images from loading screens on the left and right in ultra-wide resolutions.
Empire Total War has numerous gameplay videos which use engine assets but are presented as video clips. These videos appear to be 16:10 in aspect ratio and while presented anamorphicaly in 4:3 and 16:10, sadly stretch beyond 16:10.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
4k UHD Specific Solution & Issues