Interestingly enough, it was just before Military Tradition. Since the Aztecs North of them held their own, and the zulu Northeast had a strong envasion force, the Ottomans soon stopped expanding. It was only a matter of time the Arabs to the West got a harbor and traded for iron, thus giving them their Ansar dudes. Since the Persians had a giant force of Knights, which they ended up reserving for later since once near Turkey they would head north of me to Babylon, and then go down south... thus I had around 30 knights in my lands at all time. It wasn't long before Istanbul and all her glory was sacked. By the time the ottmans got Military Tradition it was too late for them.