This policy of foreign marriages was pursued by Iaroslav's successors but did not survive long into the 13th century.
The Grand Prince of Kiev was recognised as the nominal head of the family and overlord of the other Rus principalities.
However, he took no active part in the government of the other territories, except through the appointment of their princes from among members of his family.
The earliest generations of the so-called Rurikid family are reconstructed solely on the basis of the sparse information in the Povest' vremennykh let or 'Tale of the Years of Time', better known as the Primary Chronicle and also sometimes known as Nestors Chronicle, the extant manuscripts of the Primary Chronicle which date from the 12th century should not be taken at face value as they must have been compiled from patchy sources of information.
It is likely that the compilers exaggerated the role of Rurik's family in the 9th and 10th centuries, in order to establish a lengthy, credible history for the Russian principalities which were flourishing by the 12th century.
Archaeological evidence corroborates Scandinavian presence at Gorodishche, Timervo and other Upper Volga sites in the late 9th century.
This indicates an increasing, although still limited, number of immigrants tempted no doubt by trading opportunities, but Franklin & Shepard point out that it provides little evidence of organised government Chirovsky discusses the development of two theories concerning the origin of Russia: the "Normanistic" theory, developed by 18th century historians of German descent who supported a literal reading of the Primary Chronicle and emphasised Norse rule over the Slavs who were unable to rule themselves), and the "anti-Normanistic" theory, which posits the rapid assimilation of small groups of Norse immigrants into the local Slav community and is based on a broad interpretation of the Primary Chronicle.
In this way, various branches of the family were excluded from the succession.
For example, the descendants of Iaroslav I's oldest son by his second marriage, Vladimir Iaroslavich, never held the title as their progenitor predeceased his father.
Iaroslav I consolidated the dynasty's contacts with other European ruling families by arranging dynastic marriages.