In 2015 I was in Beek near Nijmegen, where I have lived from 1987 to 1994.
This is the view from a 5 minute walk from my home there.
What you see is the valley where the river Rhine enters the Netherlands.
The low hills on the horizon (North) are the sandy high grounds of the North East of the country, on the extreme Northern tip of which, 200 km away, lies the city of Groningen.
The Romans built a fortress town here at the border of their Empire. In the valley there lived the tribe of the Batavi, who were dedicated soldiers in the Roman army. On the Northern high ground there lived Chamavi and in the North at the coast Chauci. In the marshy areas of the West there lived old Frisians.
The Roman area belonged to the military district of Germania Inferior, which itself was part of the province of Gallia Belgica.
The capital of Germania Inferior was Cologne, which would remain one the largest cities North of the Alps throughout the Middle Ages, and became the Catholic capital of everything up to the North Sea coast.
From the Chamavi and neighbours there would come the Franks, who occupied Germania Inferior, when the Roman legions were gone fighting civil wars. Those Franks took over the border guard for the Roman Empire in Germania Inferior, and when the Roman power broke down further South, they got to rule all of Gallia. They converted to Catholicism to use the literacy of the church to help them govern an empire.
The Germans of the North East that didn’t become Franks formed the Saxons, some of which, mostly from the coast, migrated to Britannia with the Angles where they would form England.
This valley near Beek was the South Western corner of the Saxon lands.
To the South it was Frankish, and to the North West it was Frisian.
Until the 8th century, when the Franks conquered Frisia and Saxony.