:) Though it was just high profile wannabe Emperors and very noble rebels who got the noses and eyes treatments, not envoys. I mean, Lieutward of Cremona (Otto I's envoy who was supposed to bring home an imperial bride) bitches a lot about how snobby everyone treated him, but he doesn't fear for his life. For that matter, come the Crusades, one of the many things that made the Crusaders so distrustful of the Byzantines was that they exchanged envoys with the Turks and treated them respectfully. I mean, you have to consider that Alexios I. Komnenos did want military help against the Turks, but not in the sense of annihilating them. He wanted Nicea and Antioch back. (Not Jerusalem. His army wasn't nearly large enough to garnison and defend Jerusalem, see earlier posts about the civil wars depleting them.) And the Turks were already an established factor by that time. What Byzantium did and had done successfully to other enemies in the past centuries - like the Bulgars, the Rus, the Varangians - was after various wars to integrate them into the Empire and employ them. For that matter, there were some Turks already fighting for the Emperor (and there had been for the previous wannabe Emperors.) There were even some Mosques within Constantinople itself. Imagine you're a member of the First Crusade, where the preachers have very successfully dehumanized the Turks and presented the situation in the Middle East as Muslims torturing and slaughtering Christians on a daily basis, and then the fall of Nicea goes thusly:

Crusaders: *besiege Nicea, fight skirmishes, win skirmisches*

Alexios: *negotiates with Turkish garnison*

Turkish garnison, which includes the wife and children of the Sultan: *surrenders to the Emperor*

Alexios: Rejoice, we can take the city without further bloodshed! Nicea, location of the very first Christian Synod, is once again part of the Byzantine Empire!

Crusaders: But - we wanted to sack it!

Alexios: No way. Nicea has been in Turkish hands for only 20 years. Most of the people inside are former countrymen of mine. No sacking. Thanks, fellows, and have some gold from me for your kind efforts, but I got it from here.

Crusaders: Can we at least ransom the Sultana?

Alexios: Nope. The Sultan is going to stay around. He's my enemy today, but tomorrow I might need him against the Normans. For example. So I'm going to host the Sultana and her kids in the palace for a few weeks and then send her home free of ransom.

Crusaders: What kind of Christian Emperor are you anyway?

Mind you, that's the Empire in a post crisis state where Alexios knows he has to rebuild a lot, and at peak power, who knows what would have happened, but still. Mutilation is something you do to your high profile competition, not to envoys, if you're a Byzantine Roman Emperor.

You might even do it to your own child, though, which is what Romanos I. Lekapenos did with his illegitimate son Basil, to ensure he would not be a danger to his legitimate offspring. The irony is that Basil - who grew up to be one of the most powerful eunuch officials of the Byzantine Empire and managed to serve and survive several Emperors in a row - did not betray Romanos, but his legitimate sons did.