tribute. The zenith of the state's power came during the reigns of Vladimir the Great () and Prince Yaroslav I the Wise (). Both rulers continued the steady expansion of Kievan Rus' that had begun under Oleg. Vladimir had been prince of Novgorod when his father Sviatoslav I died in 972. He was forced to flee to Scandinavia in 976 after his half-brother Yaropolk had murdered his other brother Oleg and taken control of Rus. In Scandinavia, with the help of his relative Earl Håkon Sigurdsson, ruler of Norway, Vladimir assembled a Viking army and reconquered Novgorod and Kiev from Yaropolk. Although sometimes solely attributed to Vladimir/Volodymyr, the Christianization of Kievan Rus' was a long and complicated process that began before the state's formation. As early as the 1st century CE, Greeks in the Black Sea Colonies converted to Christianity, and the Primary Chronicle even records the legend of Andrew the Apostle's mission to these coastal settlements, as well as blessing the site of present-day Kyiv. The Goths migrated to through the region in the 3rd century, adopting Arian Christianity in the 4th century, leaving behind 4th- and 5th-century churches excavated in Crimea, although the Hunnic invasion of the 370s halted Christianisation for several centuries. Some of the earliest Kyivan princes and princesses such as Askold and Dir and Olha of Kyiv reportedly converted to Christianity, but Oleh the Wise, Ihor of Kyiv and Svyatoslav remained pagans. The Primary Chronicle records the legend that when Vladimir/Volodymyr had decided to accept a new faith instead of traditional Slavic paganism, he sent out some of his most valued advisors and warriors as emissaries to different parts of Europe. They visited the Christians of the Latin Church, the Jews, and the Muslims before finally arriving in Constantinople. They rejected Islam because, among other things, it prohibited the consumption of alcohol, and Judaism because the god of the Jews had permitted his chosen people to be deprived of their country. They found the ceremonies in the Roman church to be dull. But at Constantinople, they were so astounded by the beauty of the cathedral of Hagia Sophia and the liturgical service held there that they made up their minds there and then about the faith they would like to follow. Upon their arrival home, they convinced Vladimir that the faith of the Byzantine Rite was the best choice of all, upon which Vladimir made