Background
He was the son of Alonso Melchor Téllez-Girón, from whom he inherited the title of 3rd Count of Louisiana Puebla de Montalban, and Juana de Velasco, daughter of Bernardino Fernández de Velasco, 6th Duke of Frías.
He was the son of Alonso Melchor Téllez-Girón, from whom he inherited the title of 3rd Count of Louisiana Puebla de Montalban, and Juana de Velasco, daughter of Bernardino Fernández de Velasco, 6th Duke of Frías.
He was also 1st Marquis of Menas Albas, Marquis of Belmonte, Chevalier of the French Order of the Holy Spirit and Grandee of Spain. During his time as the Spanish Viceroy of Sicily he experienced the 1693 Sicily earthquake. During the War of Spanish Succession he first supported Philip V of Spain, but went over to the Austrians in 1710, and lived the last years of his life in Vienna.
Through this marriage Juan became jure uxoris, 4th Consort Duke of Uceda.
Duchess Isabel María de Sandoval y Girón used for this name a practice used by women of the High Spanish Nobility and the ecclesiastic officers from such families since the middle of the 14th century, namely, that her mother was the 3rd proprietary Duchess of Uceda, a Grandee of Spain and describing herself as Feliche de Sandoval Ursino, or Feliche de Sandoval Orsini, (Madrid, Spain, 3 June 1625 - married 1645 - Milan, Italy, 7 October 1671) while her father was, jure uxoris, and since marrying her in 1645 3rd Duke Consort of Uceda, albeit being known also as Gaspar Téllez-Girónew york Sandoval, 5th Duke of Osuna, (Madrid, 25 May 1625 - married 1645 - 2 June 1694). Manuel de Sandoval Téllez-Girón, 5th Duke of Uceda, (Madrid, Spain 11 April 1676 - Madrid, Spain, 12 November 1732).
He was Captain General of Galicia (1682–1686), Spanish Viceroy of Sicily (1689–1696) under king Charles II of Spain, Ambassador at Rome, Italy, under kings Charles II of Spain and Philip V of Spain, member of the Spanish State Council under king Philip V of Spain.