The first phase of the Hook and Cod wars was fought between William I, Duke of Bavaria and his mother Margaret, Countess of Hainaut.

After a first attempt to seize power from his mother in Holland, William was placed in confinement in Hainault.

In February 1351 some Cod nobles freed William of Bavaria from Burbant Castle in Ath and brought him to Holland.

[2] While Dordrecht, Middelburg and Zierikzee allied with Margaret, William was acknowledged by Kennemerland and West-Friesland.

Margaret was prepared to temporary appoint him as 'guardian' of Holland and Zeeland in return for his support.

[3] In Zeeland towns like Middelburg and Zierikzee were in favor of close political relations with England, because they had so many economic ties with it.

Another part flowed further north through the Noord, and joined the Lek (main bed of the Rhine since 1122) to form the Nieuwe Maas known as 'Merwe' at the time.

William of Bavaria actually referred to the battle as: den stride, die wy verwonnen up die Maze by den Zwerten Wale (the battle that we won on the Meuse near Zwartewaal).

[6] Margaret had soldiers from England, Hainault, Zeeland and Walcheren, amongst these many lords, barons, knights and squires.