I've noticed while looking at art from 'eastern' countries such as Poland, Russia and Persia, that mail armour appears to have remained prominent well into the 17th century (and possibly beyond?). In the west during this period, mail seems to be absent and armour in general was largely disappearing. What caused this disparity?
One big reason that armour survived a bit longer in eastern Europe was because the bow remained in use there longer. The Poles and Russians were engaged in near constant border skirmishes with the Ottoman Empire, Crimean Khanate, and other Tatar hordes. The Russians also were fighting eastward in their conquest of Siberia.
The Ottoman Jannisaries were famous for their use of gunpowder weapons but the bow remained popular with cavalrymen, particularly the irregular cavalry that were part of every Ottoman army and ranged ahead raiding and sacking isolated settlements and farms. The bow was popular across the Ottoman empire. Lepanto was a disaster not for the loss of the fleet (which could be replaced) but for the loss of all the trained archers and sailors. We have an account from the 1683 Siege of Vienna than an officer, Baron von Gallenfeld, was killed by a poisoned arrow defending a breach.
The Crimean Khanate raided its neighbours for over three centuries. Tatars were famous for their skill with the bow and it was an ideal raiding weapon as it was silent and generally more accurate than guns. Similarly, the Russians fighting eastward into Siberia encountered the bow being used as well as guns.
Armour fell out of use in western Europe as guns became more powerful but it still had a use on the eastern frontiers where bows were more likely to be encountered than they would further west. It was one cool difference between fighting in eastern Europe and further west. Hussars and dragoons came of age on the frontier as commanders tried to match the mobility of the Ottomans and Khanate.
Sources:
Conquest of a Continent
The Bulwark of Christendom
Enemy at the Gate