origins of the Rurik dynasty are unclear, as its namesake Rurik, a Varangian prince who allegedly founded the dynasty in 862 through the "Invitation of the Varangians", is considered to be a legendary, mythical and perhaps even entirely fictional character by modern scholars. Nicholas V. Riasanovsky (1947) stated: '...no Kievan sources anterior to the Primary Chronicle (early twelfth century), knew of Riurik. In tracing the ancestry of Kievan princes they usually stopped with Igor.' As an example, Hilarion of Kiev's Sermon on Law and Grace (1050s), praising Volodimer I of Kiev, only goes back to his father Sviatoslav I and grandfather Igor of Kiev. Even if Rurik did exist, scholars have long doubted or rejected his paternity of Igor. The connections between Rurik, Oleg and Igor, as attested in the Primary Chronicle and Novgorod First Chronicle, are tenuous at best; in all other cases, these two chronicles base any particular ruler's legitimacy on the fact that their father or grandfather previously "sat on the throne in Kiev", and never refer back to Rurik. Legitimacy in the Kievan Chronicle is also heavily based on a ruler being descended from his father and grandfather, with the exception of two 5-generation lists. Before the mid-15th century, no historical source claims that Rurik founded a dynasty; the Hypatian Codex of 1425 began its list of knyazi of Kiev with "Dir and Askold", then "Oleg", then "Igor", up to 1240, and does not mention Rurik anywhere. It was not until the 16th century that Rus' churchmen developed an explicit tradition, described in the 1560 Book of Royal Degrees by Macarius, Metropolitan of Moscow, according to which the reigning Danilovichi house of the Grand Duchy of Moscow (Muscovy) was part of a "Rurikid dynasty", which not only traced back all the way to the legendary Rurik, but was purportedly descended from a certain Prus, a supposed kinsman of Augustus Caesar. According Ostrowski (2018), the Rus' churchmen developed this concept of a R(i)urikid dynasty for the purpose of "bolstering the Muscovite dynastic state". Although many later historians would accept the 16th-century Rus' churchmen's dynastic claim that the Danilovichi were descended from Rurik, they did not accept Prus as the ancestor of the Muscovite princes. Because of these issues, various scholars have instead named the dynasty the Volodimerovichi (Volydymyrovichi), descendants of grand prince Volodimer I of Kiev. Ethnographic issues The scholarly consensus is that the Rus' people originated