Nikephoros Xiphias (, ) was a Byzantine military commander during the reign of Emperor Basil II. He played a distinguished role in the Byzantine conquest of Bulgaria, and was instrumental in the decisive Byzantine victory at the Battle of Kleidion in 1014. In 1022 he led an unsuccessful rebellion against Basil II, and was disgraced, tonsured and exiled. He is last mentioned in 1028, when he was recalled from exile and retired to a monastery. Origin Nikephoros Xiphias was born probably some time around or before 980, and was most likely the son of Alexios Xiphias, who served as the Catepan of Italy in 1006–08. Few members of the Xiphiai are otherwise known and the family's origin is unclear, but they most likely hailed from Asia Minor, like many other prestigious families of the military aristocracy of the period. Wars against Bulgaria Nikephoros appears for the first time in Emperor Basil II's Bulgarian wars, in 999/1000, 1000/1 or 1002, depending on the source. At the time he was a protospatharios, and along with the patrikios Theodorokanos, he commanded a campaign deep into Bulgarian lands. Setting out from Mosynopolis, the two generals crossed the Balkan Mountains and captured the old Bulgarian capitals of Pliska and Great Preslav, along with Little Preslav. They then plundered the Dobruja, left behind garrisons and returned to their base. It is unclear whether he was already the military governor (strategos) of Philippopolis at the time, or was appointed to it after the successful conclusion of the campaign, as John Skylitzes reports, when Theodorokanos, who is known to have previously held the post, retired due to his advanced age. Xiphias is next mentioned in the Battle of Kleidion in 1014, when Basil II was attempting to force the pass known as Kleidion or Kiava Longos, which the Bulgarians under their ruler Samuil had strongly fortified. Xiphias, still strategos of Philippopolis, suggested to the Emperor to bypass the Bulgarian positions and strike them from the rear. After Basil agreed, Xiphias led a picked infantry detachment over Mount Belasica, and on 29 July 1014, led his troops on a charge on the unsuspecting Bulgarians, who panicked and broke before the unexpected attack. For this feat, which resulted in one of the most decisive victories in the long Bulgarian war, he was rewarded with promotion to the rank of patrikios. In early 1015, Xiphias, along with Constantine Diogenes, subdued the