He had a quarrel with his son-in-law, Florent V., Count of Holland, to whom he had given his daughter Beatrice in marriage; and another of his sons-in-law, John I., Duke of Brabant, married to another of his daughters, the Princess Marguerite, offered himself as mediator in the difference.

The two brothers-in-law went together to see their father-in-law; but, on their arrival, Guy de Dampierre seized the person of the Count of Holland, and would not release him until the Duke of Brabant offered to become prisoner in his place, and found himself obliged, in order to obtain his liberty, to pay his father-in-law a tough ransom.

It was not long before Guy himself suffered from the same sort of iniquitous surprise that he had practised upon his sons-in-law.

In 1293 he was secretly negotiating the marriage of Philippa, one of his daughters, with Prince Edward, eldest son of the King of England.

Philip the Handsome, having received due warning, invited the Count of Flanders to Paris, "to take counsel with him and the other barons touching the state of the king-dom." At first Guy hesitated; but he dared not refuse, and he repaired to Paris, with his sons John and Guy.