Valentin Lavrentievich Yanin (Russian: ?; 6 February 1929 - 2 February 2020) was a leading Russian historian who authored 700 books and articles. He had also edited a number of important journals and primary sources, including works on medieval Russian law, sphragistics and epigraphy, archaeology and history. His expertise was medieval Rus' especially Novgorod the Great, where he had headed archaeological digs beginning in 1962.
Yanin was born in Vyatka. His maternal grandparents were arrested in 1937 and died in a prison camp in 1938. His father was apparently on a list to be executed but escaped this fate and moved with his family to Moscow. Yanin finished his secondary education in 1946, graduating with a Gold Medal; he matriculated at Moscow State University in 1951.
In 1954, he defended his Kandidat thesis on the monetary systems of pre-Mongol Rus. This was published as The Monetary and Weight Systems of Medieval Russia ("?-? ? ?") and has become a classic. His doctoral thesis on the posadniks of Novgorod followed in 1962 and significantly changed our understanding of the constitution of the Novgorod Republic. The book demonstrated that the office of posadnik, while subject to election every year, was often held by one man for several consecutive years, sometimes more than a decade, and then passed on to his sons or other members of his clan. It shattered the earlier image of Novgorod as a more democratic republic and showed it to be ruled by a boyar aristocracy (not unlike other medieval republics).
Yanin's monograph about the seals of Ancient Rus (2 volumes, 1970) summed up half a century of Soviet sphragistics research. After that, Yanin turned his attention to the birch bark documents of Novgorod, on which he was considered the greatest living authority (alongside Andrey Zaliznyak).
In 1964, Yanin became professor in the department of archaeology in the Faculty of History at Moscow State University.
Since 1978, Yanin had held the chair in archaeology at the Moscow University.
He was a member of the President's Committee for the Defence of the Material Culture of the Russian Federation and a member of the Consultative Committee of the Ministry of Culture of the Russian Federation.
His other awards included: