The decline of the Ottoman Empire took place during 1566 to 1807. During Suleiman long reign the Empire was at the top of political power and also thrived globally. But then the seeds of this great Empires decline had been planted already. Suleiman had grown tired of all of his campaigns and had retired leaving his Empire to stay stagnant.
After the death of Suleiman, the army had come into control of this Empire and had used it for their own profits. But the weakness of the Empire had been countered by the powers which were growing in the west. The nation states in Europe under strong monarchies were building armies as well as navies which were strong enough to take down the weak Empire.
In the Battle of Lepanto in 1571, fleets of Spain, Papal states of Italy and Venice had managed to defeat the Turks. But then navy of this Empire was rebuilt and they still ruled east Mediterranean for one more century. Another marked decline of Ottoman Empire was when the government (central) began to show weakness and part of the Empire started to function independently. But the strong army managed to prevent breakouts of rebels. New campaigns started to be taken under Murad III.
Reform efforts in the 17th century didn't help to stop the decline of Ottoman Empire. In 1603 they lost Caucasus and Azerbaijan and in 1604, Iran. Although Iran was taken over again by Muran IV, Iran posed as a military threat. Vienna was attacked by the European countries and by the start of 1683; the Empire was at war with them which lasted for around 41 years. This resulted in the loss of Balkan territory.
Another decline of Ottoman Empire was when the provinces started to be lost. Selim III had tried to reform the entire Empire was well as the army but it was in vein and he was overthrown by Mahmud II. there was warfare going on between the Greeks and Turks which led to a new military system of European armies.
Although when Mahmud died the Empire was more powerful it was still in threat from Europe. Mahmud's sons had tried to carry out other reforms but the decline of Ottoman Empire was inevitable. Czar had commented on the Empire calling it the sick man of Europe. Hence this strong Empire gradually started to lose all of its possessions.
Ottoman Empire Society and Economy:
Contrary to the popular belief which is often presented in the West, the Ottoman Empire was not a barbaric one. In fact, the Ottoman society remained isolated in time. The Ottoman Empire virtually stood stagnant, while Europe advanced.
Their economy was being primarily agrarian was based on tenant farming and weighed down by greedy tax farmers. Women were disguised and repressed, though the mothers of the Sultans and prospective Sultans in the Harem played an important role in deciding the future of the empire at times.
One of the attributes which contributes to the success of the social structure of the Ottoman Empire was the unity among its highly varied populations through an organization named as millets. The Millets were the major religious groups that were allowed to establish their own communities under Ottoman rule.