Grand Prince Igor of Kiev was a ruler of the Kievan Rus' during the 10th century. He is best known for his efforts to expand the territory of his realm and for his military campaigns against neighboring tribes, particularly the Drevlians. His reign marked a significant period in the early history of Eastern Europe. Igor was the husband of Olga of Kiev, who later became a prominent ruler in her own right. After Igor's death, she served as regent for their son, Svyatoslav I, and played a crucial role in consolidating power and influence in the region.