Final answer:
The term used by the Ottomans to describe a supreme political and military ruler was 'sultan'. This title denoted authority over the Islamic community and was prominently embodied by rulers like Suleiman I during the empire's zenith.
Step-by-step explanation:
An Arabic word used by the Ottomans to describe a supreme political and military ruler was sultan. The term sultan refers to a ruler who claims authority over the Islamic community but does not necessarily hold the title of caliph. During the peak of the Ottoman Empire, under rulers such as Suleiman I, known as “the Magnificent,” the Ottoman military became the most technologically advanced in the Mediterranean, and the empire saw dramatic expansion, including the conquering of Mecca and Medina, thereby allowing the sultans to also start calling themselves “caliphs.” The system of timars was key in the administrative and military organization, facilitating the expansion and governance of such a vast empire.