He was born in Brussels, the son of Edouard Woeste, who was of Prussian descent who became a naturalized Belgian on 15 January 1841. Edouard Woeste was consul for Prussia from 1843 to 1853 and married Constance Vauthier on 24 September 1834. In August 1855 Charles converted from Lutheranism, Prussian aristocracy's religion, to Catholicism, under the influence of his mother and father Delcourt. On 4 January 1866, he married Marie Greindl, daughter of lieutenant-general Léonard Greindl, who had been minister of war in the government of Pierre de Decker (1855).