This is the 10525th most frequent Russian word.
викингов
"Viking" (genitive plural in Russian, meaning "of Vikings").
The word 'викингов' here is used in the genitive case to indicate 'about the lives of the Vikings'.
Я недавно посмотрел документальный фильм о жизни викингов.
I recently watched a documentary about the life of the Vikings.
Here, 'викингов' is in the prepositional case to imply 'about or concerning the Vikings'.
Некоторые легенды о викингов вдохновляющие и загадочные.
Some legends about the Vikings are inspiring and mysterious.
The word 'викингов' is in the genitive case to show possession or 'belonging to the Vikings'.