On land, however, the Byzantines held the upper hand: al-Tabari reports that in spring/early summer 904, a major Byzantine army, "ten crosses with one hundred thousand men", had invaded the borderlands and plundered as far as Hadath. In November, possibly as a retaliation for the sack of Thessalonica, the Byzantine general Andronikos Doukas invaded Arab territory, and won a major victory over the forces of Tarsus and al-Massisah (Mopsuestia) at Marash (Germanikeia). Further successes followed for both sides, including the Byzantine capture of Qurus (Cyrrhus) in July 906, the raid by Ahmad ibn Kayghalagh and Rustam ibn Baradu in October 906 that reached as far as the Halys River, and Himerios' victory over an Arab fleet on St. Thomas's day, 6 October 906. In spring 907, however, Andronikos Doukas and his son Constantine defected to the Abbasids, the victims of the intrigues of Leo VI's powerful eunuch chamberlain, Samonas.