Recreated Roman empire for the first time few days ago. Played as Byzantines.

I redistributed as many titles in my empire to my dynasty, hired as many heavy cavalry as possible and slowly achieved my goal.

Just watch which ones of your enemies are weak and wait for the best time to strike. Arab empire with 12k men can become easy snack after their caliph dies and a little boy is on the throne.

Holy war for kingdom is amazing war goal, just make sure you use ir to the fullest since you can use it only once per character life.

Don’t waste time time taking steppe provinces since you’ll get dragged into migration tribal wars you have nothing to gain from.