How to Unlock Rewards in a Nomadic Empire

In 1331, the Ottomans took control of Nicaea - a seminal moment for Roman and Christian rule in Asia. And that then is followed in the next decade by Black Death which led to massive depopulation across all parts of the known world. So about 30 years after Nicaea falls, by the 1360s you find the Ottoman deep inside the Balkan interior with agi-enopo modern Idiania. They've just gone right round Constantinople. Blimey, a fiscal event. I didn't know. William.