Meadowland - Tom Holt

In 1037, a senior civil servant of the Byzantine empire faces a tedious journey to Greece, escorting the Army payroll. His only companions are a detachment of the Empire's elite Guard, recruited from Viking Scandinavia.

When the wagon sheds a wheel, he passes the time talking with two veterans, who have a remarkable story to tell; the Viking discovery of America.As he records the story, years later, he also considers its effect on the fourth member of the party; a young Norwegian guardsman who went on to become King Harald Hardradi, who died invading England

in 1066 ...