three days later, saint omer also surrendered, completing french objectives in flanders. talks at nijmegen were given a greater sense of urgency in november after william's marriage to his cousin mary, niece of charles ii of england. an anglo-dutch defensive alliance was signed in march 1678, although english troops did not arrive in significant numbers until late may; louis used this opportunity to capture ypres and ghent in early march, before signing a peace treaty with the dutch on 10 august.