The real fighting force among the Reformed Netherlanders was to be found, not among the landsmen, but in the sailors and fishermen. It is said that Admiral Coligny was the first to point this out to the Prince of Orange. He acted upon the advice, and in 1569 he had given letters of marque to some eighteen small vessels to cruise in the narrow seas and attack the Spaniards. At first they were little better than pirates,--men of various nationalities united by a fierce hatred of Spaniards and Papists, feared by friends and foes alike. William attempted, at first somewhat unsuccessfully, to reduce them to discipline and order, by issuing with his letters of marque orders limiting their indiscriminate pillage, insisting upon the maintenance of religious services on board, and declaring that one-third of the booty was to be given to himself for the common good of the country. In their earlier days they were allowed to refit and sell their plunder in English ports, but these were closed to them on strong remonstrances from the Court of Spain. It was almost by accident that they seized and held (April 1st, 1572) Brill or Brielle, a strongly fortified town on Voorn, which was then an island at the mouth of the Maas, some twenty miles west or seaward from Rotterdam. The inhabitants were forced to take an oath of allegiance to William as Stadtholder under the King, and the flag of what was afterwards to become the United Provinces was hoisted on land for the first time. It was not William, but his brother Louis of Nassau, who was the first to see the future possibilities in this act. He urged the seizure of Flushing or Vlissingen, the chief stronghold in Zeeland, situated on an island at the mouth of the Honte or western Scheldt, and commanding the entrance to Antwerp. The citizens rose in revolt against the Spanish garrison; the _Sea-Beggars_, as they were called, hurried to assist them; the town was taken, and the Spanish commander, Pachecho, was captured and hanged. This gave the seamen possession of the whole island of Walcheren save the fortified town of Middleburg. Delfshaven and Schiedam were seized. The news swept through Holland, Zeeland, Guelderland, Utrecht, and Friesland, and town after town declared for William of Orange the Stadtholder. The leaders were marvellously encouraged to renewed exertions.[263] Proclamations in the name of the new ruler were scattered broadcast through the country, and the people were fired by a song said to be written by Sainte Aldegonde, _Wilhelmus van Nassouwe_, which is still the national hymn of Holland. The Prince of Orange thought he might venture on another invasion, and was already near Brussels when the news of the Massacre of Saint Bartholomew reached him. His plans had been based on assistance from France, urged by Coligny and promised by Charles IX. "What a sledge-hammer blow (_coup de massue_) that has been," he wrote to his brother; "my only hope was from France."[264] Mons, which Louis had