The Romans and Franks
The Romans undertook the conquest of Gaul (modern France, Belgium, Luxembourg, and a portion of the Netherlands and Germany) in the first century B.C. They found the coast occupied by the Belgae, a largely Celtic people, to the south of the Rhine. To the north were two Germanic groups—the Batavians southwest of the Zuider Zee, and the Frisians northeast. The Romans established control over the region and occupied it for 400 years.
In the third century A.D. the Franks began pushing into the lower Rhine valley. As the power of the Roman Empire declined, the Franks expanded their control over all the Netherlands, the Frisians submitting last, in 719. In 754 Saint Boniface, called the Apostle of Germany, was killed by Frisians he was trying to convert.

