When Simeon I returned to Preslav "proud of the victory", he broke the negotiations with Choirosphaktes and once again invaded Byzantine Thrace, further encouraged by the death of the capable general Nikephoros Phokas. The Byzantines transferred "all themes and "tagmata"", i. e. all forces that were fighting the Arabs, to Europe. The army was commanded by the Domestic of the Schools Leo Katakalon, who lacked the ability of Phokas. The two armies clashed at Boulgarophygon in the summer of 896 and the Byzantines were thoroughly routed. A Byzantine historian wrote: