What Kind Of Relationship Did The Ottoman Empire Have With Its Eastern Neighbours?

Roughly the border with Persia fluctuated around the Van area and there was also some swapping of Baghdad but it was mostly Ottoman. The Ottomans did eventually acknowledge that the Shia weren't heretics and Nader Shah forced them to allow them to travel to Mecca. So mostly peaceful-ish coexistence at the state level with some exceptions like Nader Shah who kicked them around a bit. Eventually both of them became far more concerned with the Russians than each other.
 
What were the chances of an Ottoman/Persian/Mughal alliance against the Tsars?

Not fantastically likely. Russia isn't too much of a threat to Persia (let alone Mughals) until well after the 1600s...but by mid-1700s the fat lady has sung and it's too late to really stop the Russians in Persia. The Turks could still do it with enough Western interest, of course, but if they're also allied with Persians and Mughals they're a threat to the British (and maybe even the French), so that possibility evaporates.
 
Top