This was a Portuguese nobility title granted by King Luís I of Portugal to António José de Ávila, 1st Duke of Ávila and Bolama, a remarkable Portuguese politician and ambassador during the liberal period.
Originally, the title was granted, in 1864 as Count of Ávila (in Portuguese Conde de Ávila) and it was successively upgraded, by the same King, to Marquis of Ávila and Bolama (Marquês de Ávila e Bolama) in 1870, and finally by a royal decree dated from May 14, 1878, to Duke of Ávila and Bolama (Duque de Ávila e Bolama).
This was the first Dukedom to be granted to a commoner; in Portugal the title of Duke was traditionally granted to members of high nobility and especially to members of the royal family, such as the second sons of monarchs.
”Nobreza de Portugal e do Brasil" – Vol. II, pages 348/351. Published by Zairol Lda., Lisbon 1989.