As a lawyer, he frequently defended newspapers and journalists that had fallen foul of the government of the United Kingdom of the Netherlands, of which modern Belgium then formed the southern half.

On the outbreak of the Belgian Revolution in 1830, Van de Weyer was in Louvain, but hurried to Brussels where he became a member of the central committee of the Provisional Government of Belgium.

During his tenure as Minister in London, Van de Weyer became a "beloved and honoured friend of the royal family," as was his wife, who became close to the Queen and comforted her after the death of Albert, Prince Consort.

[8] Together, they had two sons and five daughters, who were brought up in Marylebone and on their country estate, New Lodge, in the parish of Winkfield in Berkshire: Van de Weyer died on 23 May 1874 in London, England.

[13] Through his son Victor, he was the grandfather of Major William John Bates van de Weyer (1870–1946), who was responsible for Buddleja × weyeriana.