Introductory campaign – “The Emperor’s Will” [1 campaign – 2 mission].

Winner, to be honest, that's exactly what I did. I started by taking Necropolis, rebuilt it, and then took all three Orcish Fortresses. After that, I gathered an army and attacked the main guy – I forgot his name – and voilà! Now, almost all the campaigns are unlocked, except for the last one, because you need to complete at least one campaign other than the tutorial. But you guys already know that. Thanks to everyone for the answers :) :) :)