hostilities, especially because al-Kabir continued to pay tribute to the Byzantines and al-Dawla quickly began acting as an independent ruler. Al-Hakim's persecution of Christians in his realm and especially the 1009 destruction of the Church of the Holy Sepulchre at his orders strained relations and, along with Fatimid interference in Aleppo, provided the main focus of Fatimid–Byzantine diplomatic relations until the late 1030s. Conquest of Bulgaria Basil sought to restore former territories of the Byzantine Empire. At the start of the second millennium, he fought Samuel of Bulgaria, his greatest adversary. Bulgaria had been partly subjugated by John I after the invasion of Svyatoslav I of Kiev but parts of the country had remained outside Byzantine control under the leadership of Samuel and his brothers. Because the Bulgars had been raiding Byzantine lands since 976, the Byzantine government sought to cause dissension among them by allowing the escape of their captive emperor Boris II of Bulgaria. This ploy failed so Basil used a respite from his conflict with the nobility to lead a 30,000-strong army into Bulgaria and besiege Sredets (Sofia) in 986. Taking losses and worried about the loyalty of some of his governors, Basil lifted the siege and returned for Thrace but he fell into an ambush and suffered a serious defeat at the Battle of the Gates of Trajan. Basil escaped with the help of his Varangian Guard and attempted to recover his losses by turning Samuel's brother Aron against him. Aron was tempted by Basil's offer of his sister Anna in marriage, but the negotiations failed when Aron discovered the bride he was sent was an imposter. By 987, Samuel had eliminated Aron. Another brother of Samuel, called David, was killed in 976 by the Vlachs, the guards of caravans, between Prespa and Kastoria. Although the titular emperor Roman of Bulgaria was captured in 991, Basil lost Moesia to the Bulgarians. While Basil was distracted with internal rebellions and recovering the military situation on his eastern frontier, Samuel had extended his rule from the Adriatic Sea to the Black Sea, recovering most of the territory that was controlled by Bulgaria before the invasion of Svyatoslav. He also conducted damaging raids into Byzantine territory as far as central Greece. In 996, the Byzantine general Nikephoros Ouranos defeated a Bulgarian army raid at the Battle of Spercheios in Thessaly. Samuel and his son Gabriel narrowly escaped capture. Beginning