are you chanting the Caliphate on or the Normans?
not really, the basic premise is that it started out as an interesting curiosity accidentally developed likely doomed to disappear from existence, until it is displayed to the Emperor Theophilus, who becomes facinated by the explosive substance an pours copious amounts of money into the development of ever more potent formulas of firepowder.
really the big difference, is that the Ottomans were using gunpowder weapons that had centuries of development behind them. The Roman Empire is using very early gunpowder weapons which still are mostly a fear factor weapons like the fire lance and the fire vasi (though the grenade is coming into tits own as impressive weapon).
Finley,please,using gunpowder doesn't make you European;on a point of order,the Hungarian Urban and his technicians constructed the Turkish cannon,not the Turks;they had the money and they paid for it!Constantinople had cannons but couldn't protect the length of the wall with those;they were used in the harbour...