Currently I am playing a campaign as Byzantium
I am at war with almost everyone, Hungary (who i nearly Crushed), The HRE - which i just want to hold off - i don't want to conquer into Italy too much, tho I destroyed the Venetians. It like year 1196, And i have quite a number of provinces and some good standing armies.
I really like using Byzantium because of their 'Byzantine Calvalry' they do a fine job as horse archers and can melee against archers or ride round and flank the enemy from behind when my Infantry is in combat. I mostly build armies with tons of spear men, a few units of 'byzantine infantry' as a counter-Foot Knight team, and i like to buy the Bulgarian Brigands whenever i can lol.. and around 5-6 units of Byzantine Calvarly.
I think once I start to fight against the Turks )Which is gonna be soon( i will want a mostly Calvalry army to fight in the field and a stack of pure infantry army for Sieges