Duke of Hernani is a Spanish noble title. It was created on 11 August 1914 by King Alfonso XIII of Spain

Alfonso XIII of Spain

Alfonso XIII was King of Spain from 1886 until 1931. His mother, Maria Christina of Austria, was appointed regent during his minority...

 and conferred upon his relative, Manfredo, 3rd Duke of Ansola, 2nd Marquis of Antarfe.

The 1st Duke of Hernani was a great-grandson of Infante Sebastian of Portugal and Spain

Infante Sebastian of Portugal and Spain

Sebastian Gabriel de Borbon y de Braganza, Infante of Portugal and Spain, was a royal of the 19th century, progenitor of the ducal lines of Hernani, Ansola, Durcal and Marchena, and Carlist army commander in the First Carlist War.- Family :He was born in Rio de Janeiro in 1811 as the only child of...

. He died childless in 1979 and willed the dukedom to his relative, Infanta Margarita of Spain, granddaughter of King Alfonso XIII. Her brother, King Juan Carlos I of Spain

Juan Carlos I of Spain

Juan Carlos I |Italy]]) is the reigning King of Spain.On 22 November 1975, two days after the death of General Francisco Franco, Juan Carlos was designated king according to the law of succession promulgated by Franco. Spain had no monarch for 38 years in 1969 when Franco named Juan Carlos as the...

, approved the succession and she inherited the dukedom.

Dukes of Hernani

1. 1914-1979: Manfredo, 3rd Duke of Ansola, 2nd Marquis of Antarfe
2. 1979–present: Infanta Margarita of Spain, Duchess of Soria

The 2nd Duchess has a son and a daughter, who are entitled to inherit the dukedom.