I just finished listening to Empires of the Sea by Roger Crowley (author of City of Fortune) today. It is supposedly about the Siege of Malta and the Battle of Lepanto, but these events actually make up about half the book. The larger narrative focus is on the Ottoman and Christian efforts to dominate the Mediterranean Sea throughout the 16th century.
Though many are familiar with corsairs such as Barbarossa, they were part of a larger Ottoman strategy for control of the Mediterranean. They terrified Christian civilians and took thousands of them into slavery from France, Italy and Spain. Combined with Ottoman naval dominance, the Turks ruled the eastern Mediterranean.
The Christians were not as fortunate. They were often too divided to engage in any concentrated action against the Ottomans, for even if an alliance was formed, it would soon fall apart because of bickering and differing objectives. The Knights of saint John were the closest Christian counterparts to the corsairs, and they continued to be a thorn in the Sultan's side even after they were ejected from Rhodes.
The corsair raids and Ottoman naval victories caused Christian morale to crater, which is why the victories of Malta and Lepanto were so important. They both showed that the Ottomans could be defeated. The Ottoman defeat at Malta was important for another reason as well. It permanently divided the Mediterranean into Muslim and Christian zones (though this was not apparent at the time). The Ottomans would hold sway in the east, while Spain held the West.
Lepanto, much like the Battle of Tours, was once held as a turning point in saving Europe from the Islamic onslaught. That this interpretation has fallen out of fashion in recent decades should not diminish the importance of Lepanto. Not only did it prove to the Ottomans and Christians alike that Christian navies could meet Ottoman fleets on equal terms, the battle destroyed the Ottoman fleet. While they did rebuild the very next year, the experience seems to have stolen the wind from theirs sails. Henceforth, Ottoman competition with the Hapsburgs would be primarily through attacks on Hungary and Vienna.
A good book overall, but I found that it did not discuss the ramifications of each battle in the long term, preferring to stick to the years after the battles, sketching out the lives of the participants and leaving the reader to draw his or her own conclusions. On the other hand, I did enjoy the background leading up to the two battles, which did much to explain why they were fought where they were and how they were.