The first recorded Slavic tribes living in the regions of Red Rus' were the White Croats and Dulebes. In the year 907 the Dulebs were involved in the military campaign against Constantinople led by Rus' Prince Oleg of Novgorod. This was the first significant evidence of political affiliation among the native tribes of the Red Rus' region. According to Nestor the Chronicler some strongholds in West Part of Red Rus' were conquered by Vladimir the Great in 981, and in 992 or 993 Vladimir carried out a military campaign against the Croats. Around that time the city of Volodymyr was established in honor of him which became the main center of political power in the region. During the 11th century western border cities including Przemysl, were twice annexed by the Kingdom of Poland (1018–1031, and 1069–1080). In the meantime, Yaroslav the Wise established a "solid foot" in the region founding the city of Jarosław.