Igor Svyatoslavich was a notable prince of the Kievan Rus, ruling in the late 10th and early 11th centuries. He was the son of Svyatoslav I, a prominent ruler, and is best known for his military campaigns and efforts to strengthen the state. His reign is often marked by conflicts with neighboring tribes and the consolidation of power within the region. Igor's most famous military expedition was against the Byzantine Empire, which ultimately led to his defeat and capture. He is also remembered for his marriage to Olga of Kiev, a significant figure in her own right, who later became a saint in the Orthodox Church.