The marshes were crossed by dykes, and two streams were dammed so as to fill a broad deep moat round the lines and flood the country outside.

Other lines, three miles long, connected the investing lines with the village of Crevecceur on the Meuse, Frederick Henry's base of supplies, which were brought by water from Holland.

These works completed, approaches were at once opened against the forts of St Anthony and St Isabella, the task being entrusted to the English and French troops.

The court of Brussels now began to take serious measures for relieving the town.

At first regarding _Bolduc la pucelle_ as impregnable, they had been pleased to hear that the prince had committed himself to an enterprise certain to be a dismal failure.