In open battle at Mook, however, [Sidenote: April 14, 1574] the Spanish veterans again achieved success, defeating the patriots under Louis of Nassau, who lost his life.

The beginning of the year saw the investment of Leyden in great force.

The heroism of the defence has become proverbial.

When, in September, the dykes were cut to admit the sea, so that the vessels of the Beggars were able to sail to the relief of the city, the siege was raised.

It was the first important military victory for the patriots and marks the turning-point of the revolt.