Final answer:
The Ottoman Empire strengthened its navy to protect overseas territories, ensure control over trade routes, and respond to military challenges, especially after facing a significant defeat at the Battle of Lepanto in 1571.
Step-by-step explanation:
The Ottoman Empire increased the size and power of its navy for several reasons throughout its history. Initially, as the Ottoman Empire expanded to include coastal regions and control strategic waterways, the necessity of a powerful navy became apparent. Elements of control included protecting its overseas territories, such as their advances into North Africa and the Red Sea, and engaging in naval battles to maintain dominance, as seen in conflicts with the Portuguese in the Indian Ocean. Growing trade obligations and the need to secure trade routes, particularly those valuable like the spice trade, were other crucial factors.
However, post the pinnacle era of the empire during Sultan Suleiman I's reign, which saw many successful conquests and territorial expansion, the Ottoman navy was significantly challenged. The catastrophic defeat at the Battle of Lepanto in 1571 against the Holy League marked the end of Ottoman naval supremacy in the Mediterranean. Consequently, the Ottoman naval forces needed to be strengthened not only for trade purposes and protection of territories but also to respond to European military advancements and maintain effective control over their domains.
In the face of threats from European powers, the empire recognized the value of technological and military modernization. This led them to send officers to European countries for training, invite European advisers, and pursue more significant advancements in their own military technologies and strategies. This focus on strengthening their navy was also a part of broader efforts to make their control over core territories more efficient and to respond to European naval expansion, especially with the rise of nationalism and nation-states that pressed for dominion in international markets and colonies.