In compliance with the treaty made by his father after the Siege of Dorostolon ( 971 ) , Vladimir sent 6,000 men to Basil .
In 988 , Basil II requested military assistance from Vladimir I of Kiev to help defend his throne .
In compliance with the treaty made by Vladimir I 's father after the Siege of Dorostolon ( 971 ) , Vladimir I sent 6,000 men to Basil .
In 988 , Basil II requested military assistance from Vladimir I of Kiev to help defend his throne .