Title: Classical Age of the Ottoman Empire
Content:  The Classical Age of the Ottoman Empire (Klasik Çağ) concerns the history of the Ottoman Empire from the Conquest of Constantinople in 1453 until the second half of the sixteenth century, roughly the end of the reign of Suleiman the Magnificent (r. 1520–1566). During this period a system of patrimonial rule based on the absolute authority of the sultan reached its apex, and the empire developed the institutional foundations which it would maintain, in modified form, for several centuries. The territory of the Ottoman Empire greatly expanded, and led to what some historians have called the Pax Ottomana. The process of centralization undergone by the empire prior to 1453 was brought to completion in the reign of Mehmed II.
Title: Rise of the Ottoman Empire
Content:  local warlords Ghazis and vassals (Beys) to maintain control over their realm. By the middle of the fifteenth century the Ottoman sultans were able to accumulate enough personal power and authority to establish a centralized imperial state, a process which was brought to fruition by Sultan Mehmed II (r. 1451-1481). The conquest of Constantinople in 1453 is seen as the symbolic moment when the emerging Ottoman state shifted from a mere principality into an empire therefore marking a major turning point in its history. The cause of Ottoman success cannot be attributed to any single factor, and they varied throughout the period as the Ottomans continually adapted to changing circumstances. The earlier part 
Title: History of the Middle East
Content:  By the early 15th century, a new power had arisen in western Anatolia, the Ottoman Empire. Ottoman khans, who in 1453 captured the Christian Byzantine capitol of Constantinople and made themselves sultans. The Mamluks held the Ottomans out of the Middle East for a century, but in 1514 Selim the Grim began the systematic Ottoman conquest of the region. Syria was occupied in 1516 and Egypt in 1517, extinguishing the Mameluk line. Iraq was conquered almost in 40 years from the Iranian Safavids, who were successors of the Aq Qoyunlu. The Ottomans united the whole region under one ruler for the first time since the reign of the Abbasid caliphs of the 10th century, and they kept control of it for 400 years, despite brief intermissions created by the Iranian Safavids 
Title: Transformation of the Ottoman Empire
Content:   While in 1550 the Ottoman Empire was a patrimonial state in which all power was held exclusively by the sultan, by 1700 it had experienced a political transformation whereby the sultan's monopoly on power was replaced with a multi-polar system in which political power was informally shared among many different individuals and factions. This process came about gradually, and was not unopposed. Certain rulers, such as Osman II and Murad IV, sought to reverse this trend and reestablish absolute power for themselves. For his efforts, Osman II became the victim of regicide in 1622, the significance of which one historian has 
Title: Anatolian rug
Content:  Around 1300 AD, a group of Turkmen tribes under Suleiman and Ertugrul moved westward. Under Osman I, they founded the Ottoman Empire in northwestern Anatolia; in 1326, the Ottomans conquered Bursa, which became the first capital of the Ottoman state. By the late 15th century, the Ottoman state had become a major power. In 1517, the Egyptian Sultanate of the Mamluks was overthrown in the Ottoman–Mamluk war. Suleiman the Magnificent, the tenth Sultan (1520-1566), invaded Persia and forced the Persian Shah Tahmasp (1524–1576) to move his capital from Tabriz to Qazvin, until the Peace of Amasya was agreed upon in 1555. As the political and economical influence grew of the Ottoman Empire, Istanbul became a meeting point of diplomats, merchants and artists. During 
Title: Transformation of the Ottoman Empire
Content:   The Transformation of the Ottoman Empire, also known as the Era of Transformation, constitutes a period in the history of the Ottoman Empire from c. 1550 to c. 1700, spanning roughly from the end of the reign of Suleiman the Magnificent to the Treaty of Karlowitz at the conclusion of the War of the Holy League. This period was characterized by numerous dramatic political, social, and economic changes, which resulted in the empire shifting from an expansionist, patrimonial state into a bureaucratic empire based on an ideology of upholding justice and acting as the protector of Sunni Islam. These changes were in large part prompted by 
Title: Women in Turkey
Content:  In the course of the 16th and 17th centuries during the Sultanate of Women, women of the Imperial Harem had extraordinary influence on politics of Ottoman Empire. Many of the Sultans during this time were minors and it was their mothers, like Kösem Sultan, or sometimes daughters of the sultan as Mihrimah Sultan, leaders of the Harem, who effectively ruled the Empire. Most of these women were of slave origin. The period started in 1520 during the reign of Suleiman the Magnificent until 1656, the reign of Mehmed IV. During the decline of the Ottoman Empire in the 19th century, educated women within the elites of Istanbul began 
Title: Ottoman Empire
Content:  The Ottoman Empire ( Devlet-i ʿAlīye-i ʿO s mānīye, ; Osmanlı İmparatorluğu or Osmanlı Devleti; Empire ottoman) was an empire that controlled much of Southeastern Europe, Western Asia, and Northern Africa between the 14th and early 20th centuries. It was founded at the end of the 13th century in northwestern Anatolia in the town of Söğüt (modern-day Bilecik Province) by the Turkoman tribal leader Osman I. After 1354, the Ottomans crossed into Europe and with the conquest of the Balkans, the Ottoman beylik was transformed into a transcontinental empire. The Ottomans ended the Byzantine Empire with the conquest of Constantinople 
Title: Ottoman Empire
Content:   The son of Murad II, Mehmed the Conqueror, reorganized both state and military, and on 29 May 1453 conquered Constantinople, ending the Byzantine Empire. Mehmed allowed the Eastern Orthodox Church to maintain its autonomy and land in exchange for accepting Ottoman authority. Due to tension between the states of western Europe and the later Byzantine Empire, the majority of the Orthodox population accepted Ottoman rule as preferable to Venetian rule. Albanian resistance was a major obstacle to Ottoman expansion on the Italian peninsula. In the 15th and 16th centuries, the Ottoman Empire entered a period of expansion. The Empire prospered 
Title: History of the Ottoman Empire
Content:  1646 created a significant crisis of rule, which the dominant women of the Imperial Harem filled. The most prominent women of this period were Kösem Sultan and her daughter-in-law Turhan Hatice, whose political rivalry culminated in Kösem's murder in 1651.  This period gave way to the highly significant Köprülü Era (1656–1703), during which effective control of the Empire was exercised by a sequence of Grand Viziers from the Köprülü family. On 15 September 1656 the octogenarian Köprülü Mehmed Pasha accepted the seals of office having received guarantees from the Valide Turhan Hatice of unprecedented authority and freedom from interference. 

Question: who ruled the ottoman empire in the 1500s?
Answer: Selim I.