After the defeat at Ankara, the sons of Bayezid I fought a decade-long civil war. Mehmed I eventually defeated his brothers and is often called the 'second founder' of the empire for restoring its unity.

The Vilayet Law of 1864 reorganized the provincial administration into Vilayets with more centralized control, modeled after the French department system, as part of the Tanzimat reforms.

The Janissaries were the 'spiritual sons' of the Bektashi order. The order's emphasis on saint-veneration and its inclusive rituals suited the backgrounds of the converted Christian soldiers.

The Treaty of Kuchuk-Kainarji (1774) following a defeat by Russia was a massive blow. It granted Russia the role of 'protector' of Orthodox Christians in the Ottoman Empire and led to the eventual annexation of Crimea.

The Köprülü family provided a series of exceptionally capable Grand Viziers in the mid-to-late 17th century who cracked down on corruption and led military revivals, briefly reversing the empire's decline.

Kara Mustafa Pasha was the commander whose failure at Vienna led to his execution by Sultan Mehmed IV and the beginning of the empire's territorial losses in the West.

The Ottomans used Turkic/Arabic terms: Sanjaks (districts) were part of Eyalets (provinces). The system was later reformed into Vilayets in the 19th century. 'Province' is the English translation, not the official name.

The Divan was the high council where the Grand Vizier and other ministers met to discuss state affairs, justice, and military planning. The Sultan often watched the proceedings from behind a grilled window.

Selim I defeated Shah Ismail of the Safavid Empire at Chaldiran, securing Eastern Anatolia and stopping the westward spread of Shia influence into Ottoman lands.

In the 17th century, the practice of fratricide was replaced by the 'Kafes' system. Princes were confined to the palace until they either became Sultan or died, which often led to Sultans ascending the throne with no political or military experience.