states in the introduction to Eaters of the Dead
(1976), that the book is a direct translation of the writings of the historical
traveller Ahmed Ibn Fadlan
, who ran into Viking
s (a tribe of Rus
) on his travels to the north.
In an afterword Crichton wrote in 1992, he admits that only the first three chapters are in fact from Ibn Fadlan's manuscript, while the rest of the story is pure fiction. Nonetheless, Crichton has managed in a very good way to preserve the style of Ibn Fadlan throughout the whole book.
To conclude, the descriptions of the vikings in the first three chapters are a real, historical, first hand account from an Arab scribe. The rest of the story is a retelling of Beowulf.