More recently, Nazi troops massacred thousands of people at the Babi Yar ravine in this city, which was heavily affected by radiation from Chernobyl.  
Much of the early history of this city is contained in the Primary Chronicle  written by a monk named Nestor. One ruler of a polity named for this city helped Basil II put down the rebellion of Bardas Sclerus and married Basil II's sister Anna Porphyrogeneta. That man's son was forced to contest with his half-brother Sviatopolk the Accursed for the throne, and he constructed the Saint Sophia Cathedral in this city. More recently, Nazi troops massacred thousands of people at the Babi Yar ravine in this city, which was heavily affected by radiation from Chernobyl.  For 10 points, name this city that was converted to Christianity under Vladimir the Great, the current capital of Ukraine.
Much of the early history of this city is contained in the Primary Chronicle  written by a monk named Nestor.
Kiev [Accept Kyiv]