1. HRH Doña Blanca de Castilla Maria de la Concepción Teresa Francisca de Asis Margarita Juana Beatriz Carlota Luisa Fernanda Adelgunda Elvira Idelfonsa Regina Josefa Micaela Gabriela Rafaela Infanta of Spain
* Graz, September 7th, 1868
† Viareggio, October 25th, 1949
On February 4, 1867, at Frohsdorf in Austria, Carlos married Princess Margarita of Bourbon-Parma, daughter of Duke Charles III of Parma and of his wife, Louise Marie Thérèse of France. The couple had five children: Note the first child is Blanca.
* Blanca de Borbón y Borbón-Parma (1868-1949) m in 1889 at Frohsdorf Archduke Leopold Salvator of Austria, Prince of Tuscany and had issue.
* Jaime de Borbón y Borbón-Parma (1870-1931)
* Elvira de Borbón y Borbón-Parma (1871-1929) died unmarried but with issue.
* Beatriz de Borbón y Borbón-Parma (1874-1961) married in 1892 Fabrizio Massimo, Principe di Roviano at Venice
* Alicia de Borbón y Borbón-Parma (1876-1975) married (1) in 1897 Friedrich, Prince von Schönburg-Waldenburg at Venice and had issue, divorced 1903; (2) in 1906 at Viareggio, Lino del Prete and had issue.