This place, very strong by art and still stronger by-nature, was the
other key to all north Netherland--Friesland, Groningen, and Drenthe.
Should it fall into the hands of the republic it would be impossible for
the Spaniards to retain much longer the rich and important capital of all
that country, the city of Groningen. Coeworden lay between two vast
morasses, one of which--the Bourtange swamp--extended some thirty miles
to the bay of the Dollart; while the other spread nearly as far in a
westerly direction to the Zuyder Zee. Thus these two great marshes were
a frame--an almost impassable barrier--by which the northern third of the
whole territory of the republic was encircled and defended. Throughout
this great morass there was not a hand-breadth of solid ground--not a
resting-place for a human foot, save the road which led through
Coeworden. This passage lay upon a natural deposit of hard, dry sand,
interposed as if by a caprice of nature between the two swamps; and was
about half a mile in width.

The town itself was well fortified, and Verdugo had been recently
strengthening the position with additional earthworks. A thousand
veterans formed the garrison under command of another Van den Berg, the
Count Frederic. It was the fate of these sister's-children of the great
founder of the republic to serve the cause of foreign despotism with
remarkable tenacity against their own countrymen, and against their
nearest blood relations. On many conspicuous occasions they were almost
as useful to Spain and the Inquisition as the son and nearly all the
other kinsmen of William the Silent had rendered themselves to the cause
of Holland and of freedom.

Having thoroughly entrenched his camp before Coeworden and begun the
regular approaches, Maurice left his cousin Lewis William to superintend
the siege operations for the moment, and advanced towards Ootmarsum, a