Tirso's mother was María Lorenza de Lardizábal y Otazu (1806-1889);[REF] his maternal grandfather, Juan Antonio de Lardizábal y Altuna, XII Lord ("Señor") of Laurgain and VII Lord ("Señor") of Amézqueta, was among the largest landowners in Guipúzcoa.
In 1867 he married[REF] Ramona Álvarez de Eulate y Moreda (1846-1927),[REF] also from a noble lineage[REF] related mostly to Guipúzcoa and Navarre [REF].