How to form an army from Corps?

[Twotribes]

I know you can split stuff can you form it too?

[AlvaroSousa]

corps and armies are the same thing.

German/USA corps = Russian Army in strength and size roughly. They are just labeled differently just like history.

Reason is because Russians had smaller divisions and it was easier to manage with crappy leaders.

[Chocolino]

I assume you want to know how to merge units mechanically in the game interface.

You move one small unit into/onto another until a "plus" icon shows. Then you right click and the units are merged.

Both units that merge must be smaller than a large corps (e.g. 2 divisions form a small corps or a division and a small corps form a large corps).

If you want to create armies - only the Russians can do that (as Alvaro stated, a Russian army is just another name for a corps of the other nations.

[toddtreadway]

I think you need to hold down the ALT key after selecting one and then move the mouse cursor over the other unit. A + sign will appear, allowing you to click on the unit to join them.