1081–1180", he stresses the wisdom of John's approach to warfare, which focused on siege warfare rather than risky pitched battles. Birkenmeier argues that John's strategy of launching annual campaigns with limited, realistic objectives was a more sensible one than that followed by his son Manuel I. According to this view, John's campaigns benefited the Byzantine Empire because they protected the empire's heartland from attack while gradually extending its territory in Asia Minor. The Turks were forced onto the defensive, while John kept his diplomatic situation relatively simple by allying with the Western Emperor against the Normans of Sicily. Overall, John II Komnenos left the empire a great deal better off than he had found it. Substantial territories had been recovered, and his successes against the invading Petchenegs, Serbs and Seljuk Turks, along with his attempts to establish Byzantine suzerainty over the Crusader States in Antioch and Edessa, did much to restore the reputation of his empire. His careful, methodical approach to warfare had protected the empire from the risk of sudden defeats, while his determination and skill had allowed him to rack up a long list of successful sieges and assaults against enemy strongholds. By the time of his death, he had earned near universal respect, even from the Crusaders, for his courage, dedication and piety. His early death meant his work went unfinished; historian Zoe Oldenbourg speculates that his last campaign might well have resulted in real gains for Byzantium and the Christian cause. Manuel I Komnenos John's chosen heir was his fourth son, Manuel I Komnenos. According to Niketas Choniates, a historian of Byzantium, Manuel was chosen over his elder surviving brother because of his ability to listen carefully to advice. Manuel was known for his lively and charismatic personality; he was known for his love for all things from Western Europe. Manuel arranged jousting matches, even participating in them, an unusual experience for the Byzantines. Manuel himself is generally considered the most brilliant of the four emperors of the Komnenos dynasty; unusual for a Byzantine ruler, his reputation was particularly good in the west and the Crusader states, especially after his death. The Latin historian William of Tyre described Manuel as "beloved of God... a great-souled man of incomparable energy", [whose] "memory will ever be held in benediction". Manuel was further extolled by Robert of Clari as a "generous and worthy man". Manuel dedicated himself to restore