Tzimiskes then seized a pass in Sayf al - Dawla 's rear , and attacked him during his return .
In spring 956 , Sayf al - Dawla pre-empted Tzimiskes from a planned assault on Amida , and invaded Byzantine territory first .
Tzimiskes then seized a pass in Sayf al - Dawla 's rear , and attacked Sayf al - Dawla during Sayf al - Dawla 's return .
In spring 956 , Sayf al - Dawla pre-empted Tzimiskes from a planned assault on Amida , and invaded Byzantine territory first .