​The tribe originated in the plains of Sangaria, on the border with the Gobi Desert, and marched southward. It penetrated Armenia and advanced towards Anatolia Eyalet, thus taking the stage of history. On that stage, there were dying empires, such as the Seljuk Empire, those in the process of collapse such as the Arabian Empire and others wallowing in a stage of loss such as the Eastern Roman Empire and its capital Byzantine whose primary concern was the question of how many angels could stand on the head of a pin.
Over the 300 years that followed the death of Suleiman Shah, the Ottoman Empire expanded from the Albanian coast along the Adriatic Sea to the borders of Persia and from Egypt to Caucasus, thanks to a successive chain of great sultans, the latest of which was the 10th Sultan, Suleiman the Magnificent. After Suleiman, power was passed down to Selim II, also known as Selim the Sot and since then the Ottoman Empire started its decline. 
History cannot let the era of Suleiman the Magnificent go unnoticed. Hungary and Crimea were brought under his rule as submissive states. European kings tripped over themselves to win him over and brought him tribute. His troops were blocking the way towards the East. His fleet patrolled and controlled the Mediterranean and North Africa acknowledged his leadership. Constantinople kneeled before him and was declared capital of his Empire. He tried, at least once, to make the world bow down to him. In 1580, he approached Vienna and grabbed the entire Christian world by the throat. The Ottoman army was the largest in Europe and the capital, Istanbul, was five times bigger than Paris. The Ottomans tightened their grip on the Islamic World and cast their shadow over Europe.
The empire turned into a military state prepared to conquer and initiate holy wars. By 1520, it attained self-sufficiency to food, metals and land. The Ottoman troops were nulli secondus , i.e. second to none. They included 87,000 cavaliers and 16,000 janissaries tasked with waging wars. Ottoman Turkey was always in a state of war. The Sultan had infinite power and the only threat to such power came from his kinsmen. Turkey constituted a challenge for the West and was a primary factor in driving western European countries towards military revolutions. 
Ottoman rule had major influence on every sector of the Balkan community. Most of the aristocracy there was eradicated and the rest of it was swallowed by the ruling caste after the Sultan seized their property. Although they used to pay taxes, work on land and serve in the military, peasants were still treated far better than previously. The Ottomans did not coerce Balkan natives into abandoning their culture or converting their faith as was the norm at that time. Rather, they allowed them to uphold their doctrines and to perform mixed marriages. Some historians believe that it was this policy that prolonged the Ottoman rule of the Balkans for 400 years. 
Charles V, the holy and most Catholic Roman emperor, lost a great deal due to the Ottomans’ resolve to start a holy war against Christianity. His attempt to face up to the Ottomans in North Africa failed as he was defeated in Tunisia and Algeria. Charles V admitted that the Turkish threat forced him to put aside religious matters; he took advantage of the Ottoman-Persian conflict to achieve his sole victory over the Lutherans. France lent Suleiman a helping hand to confront the Habsburg troops in Vienna and the Ottoman triumphs and expansion in Western Europe were largely because of the Christian disputes among themselves in Europe. 
Emperor Ferdinand of Spain took over five colonies in North Africa including Tripoli and Algeria and secured Spain’s sea routes between Sicily, Sardinia and Tunisia. However, the Ottomans built a huge naval fleet that enabled them to take over Egypt and re-threaten the Spanish acquisitions. With Barbarossa joining the Ottoman fleet, Spain irrevocably lost Tunisia and Algeria and its connecting routes with Milan, Napoli and Sicily grew unsafe. When Philip II of Spain decided to confront Suleiman, his venture cost him 27,000 ships and 10,000 captives that were sold into slavery at the Istanbul slave market. 
The final confrontation between the Ottomans and the Europeans became inevitable and played itself out in the 1571 naval battle of Lepanto where the world’s most powerful naval fleets met. The Christians prevailed in the battle, losing only ten ships out of 208 and 15,000 sailors, while the Turks suffered the loss of 117 ships out of 270, the sinking of another 117 and the death of 30,000 sailors, the biggest Ottoman defeat after the one in 1902. According to historians, this battle signaled the start of the decline of Ottoman Turkey, but nothing was mentioned in the Turkish archives. In fact, the Sultan retaliated by rebuilding a new fleet. Within six months of the Lepanto defeat, the Turks had built 200 new ships and captured Cyprus, then Tunisia, forcing the Spanish out.