Byzantium

[Frederick_I_Barbarossa]

Byzantium is one of my favorite factions in the entire game (behind, of course, HRE). I just wish the Orthodox factions had a Pope-like figure in the person of the Patriarch, but oh well.
One thing I have noticed in my numerous campaigns as Byzantium is that capturing Durazzo almost ALWAYS leads to war with Venice. I find it to be an excellent strategy to avoid taking Durazzo and avoid conflict with most of the European powers. I tend to concentrate on mopping up Rebels (I love sending expeditions north across the Black Sea and capturing the Crimea) and, when war for expansion becomes inevitable, attacking the Muslims.

[Gingivitis]

Durazzo is such a dump anyway it's easy to avoid taking it. I never take it unless I already have Ragusa. If you don't have Zagreb pretty much all of Venice's attacks come for Ragusa so you can keep an under-teched Durazzo safe by fighting at a developed castle instead of a cheezy wooden wall. Once I got Ragusa taking Italy was a snap. As I posted somewhere else, when advancing I lose a ton of infantry but keep my cavalry and archers pretty safe. Italy has developed barracks everywhere so I can replace infantry losses quickly and not rely on shipping units back and forth from Ragusa. Once in Italy the higher base conversion% of Orthodox churches coupled with the Ikoner's Studio means I can move priests ahead to the next target while the one I just took gets a steady conversion. Throw in a few spies and blow up some buildings and you can cause any city in Italy to rebel eventually since only one or 2 seem to have spies in their own cities. Works great if you're just at war with Venice and don't want to get into it with Milan, HRE, or the Papacy but still want to expand. If you're in Italy you may be close to the 45 province limit, but if not make sure it's a priority to take a city on the west coast you have a port there so you don't have to sail around Naples.