The literary history of the title "Grand Duke" is somewhat different from tracked above real history.
In the annals of the 14th century princes who ruled in the 10th – 13th centuries are still titled princes. In the Novgorod chronicle this tradition was preserved until the very end. In the Moscow chronicle, these princes begin to named grand dukes – since the beginning of the 15th century episodically, and from the fourth quarter of the 15th century systematically. Perhaps this is due to the formation of the state ideology of the Moscow state.