Complex sentence: This victory provoked Byzantine Emperor Nikephoros I to settle Anatolian populations along the frontier to protect it and to attempt to retake and refortify Serdica, although this enterprise ultimately failed.
Split into simpler sentences: This victory provoked the reaction of the Byzantine Emperor Nikephoros I, who proceeded to settle Anatolian populations along the frontier to protect it. He also attempted to retake and refortify Serdica, although this enterprise ultimately failed.