The Ottoman Empire was established by Osman I in 1299 CE. They wrestled political control of Anatolia from the Seljuks who were in decline because of internal political problems. The Ottoman Turks would be the dominant empire in the Middle East until 1923 when the dynasty could not recover from the defeat of World War I. There were a number of factors that contributed to the success of the Ottoman Empire.
The rise of the Ottoman Empire coincided with the fall of another powerful player in the region. The Byzantine Empire was in serious decline due to weak leadership and the lasting effects of the Crusaders from Western Europe. The decline of the Byzantine created a void in economic, political, and social power that the Ottomans were able to take advantage of. The Turks were able to capture the city of Constantinople in 1453 under Mehmed the Conquerer, and it was made the imperial capital and renamed Istanbul. The weakness of the Byzantine Empire was a major contributor to the expansion of Ottoman rule.
Another reason for the success of the Ottomans is tied to religion. The subjects of the Ottoman Empire were devout Muslims and they believed they were on a mission to expand Islam. The religious leaders of the empire were also the political leaders. This made it easy for the subjects to obey their rulers. This prevented the political turmoil that occurred in other dynasties.
The military of the Ottoman Empire was another reason for its success. The sultan was in charge of the military, which was very well organized and funded. Military concepts and procedures pervaded the operations of the court, ministries, and bureaucracy. Warfare was the business of the state, and that business was very lucrative for the Turks. Each year the sultan planned and usually led a carefully designed campaign intended to achieve a particular aim--the conquest of a new territory, the reduction of a troublesome enemy, or the suppression of a rebellion--within the season allotted for it. A new force was assembled for each campaign season. They recruited soldiers from their conquered peoples and at the height of its military power the Ottoman forces totaled over 20,000 men.
technological advancements in military weapons
in my view, these 3-4 factors were quite significant
1. the decline of the Arabs, who in fact, the Ottoman ('Utmanli') Turks succeeded.
2. Unified and centralized system of military command that helped the Turks in their earliest campaigns in East and West
3. Divisions betwen the Christian kingdoms of Europe, especially between the Roman and Greek Orthodox churches, which allowed the Ottomans easier access into europe and also led to the fall of Constantinople in 1453.
4. Their early dynamism and energy, which allowed for maximum expansion before they too in turn, became 'sick' and fell into a long decline.
I hope these are useful