I think I'll play the Turks pretty conservatively - building a large trade empire and then expanding and attacking en masse after the GH arrives. I have actually never had a game go long enough for it to even happen to me. I was thinking of expanding west as much as my navy allows, then waiting for the Horde - once it arrives it'll be in the Byzantine's area (probably) and that will weaken the Byz for my exploitation.

Then again I might get greedy and take Const. even though I hope to make the Byz to be one of my closest Allies and concentrate on invading countries far from me.