SAN LORENZO DE EL ESCORIA, SPAIN - OCTOBER 08:  Princess Elena of Spain and Princess Cristina of Spain pay their respects at El Escorial Monastery for a Corpore Insepulto Mass of Spain's Duke of Calabria, Carlos de Borbon Dos Sicilias on October 8, 2015 in San Lorenzo de El Escorial, Spain. Carlos de Borbon was born in 1938 and attended school with King Juan Carlos, where they became very good friends. He ranked first in the line of succession after the descendants of Don Juan Carlos and Queen Sofia.  (Photo by Juan Carlos Hidalgo - Pool/Getty Images)