 The Byzantine chronicler Theophanes the Confessor claims that the vanguard alone numbered 15,000 men and the entire invasion force 100,000, clearly a grossly inflated number.Theophanes also records a certain Amr as Mu'awiya's second-in-command, but Arab sources are unambiguous in this regard.The Arab army moved west into northwestern Asia Minor, and the vanguard under al-Battal attacked and sacked the town of Gangra in Paphlagonia and a place called in Arab sources Tabya, possibly the fort of Ateous in Phrygia.