Holtreman is a spelling version of the Oultreman family name. The Holtreman name was adopted in Portugal by an Oultreman’s family branch originally from Valenciennes. In the early 17th century, a knight called Jean (John) Houltremant (or d’Oultreman) served the Count of Vila Real in the reign of Philip III of Portugal (Philip IV of Spain). Jean Houltremant descended from an old lineage from the County of Flanders and the County of Hainaut being a grandson of Jacques d’Oultreman dit Houltreman, adviser of his majesty at Namur. Jean married Ana Antónia Nunes, daughter of Manuel Nunes and wife Ana Nunes, landowners of the Anadia region in Portugal.
After the Portuguese Restoration War, Jean descendency is believed to have adopted his wife's family name of Nunes, and moved to Pousaflores into his wife's family lands. The Holtremant name was later recovered in the 18th century by Bartolomeu Nunes Holtremant, Knight of the Order of Christ and by his cousin - and godson - Manuel Ribeiro Holtremant, Knight of the Order of Saint James. Due to Portuguese pronunciation, all their descendants have adopted the Holtreman spelling. In Portugal, the family is better known because of the foundation of Sporting Clube de Portugal (often erroneously known as "Sporting Lisbon").
The d'Oultreman family obtained several recognition of nobility from both the Habsburgs's Austrian and Spanish branches, and from Charles I of Portugal. In the County of Flanders and the County of Hainaut, both Flemish and French were spoken across both counties, explaining why the name suffered minor spelling changes depending on where the family member lived or was born. The most commons are Oultreman (or Houltreman) and Oultremant (or Houltremant).
There are two main versions for the origin of the name Oultreman:
- The most likely is that the family descends from the Knight known as the Oultreman of Ghent (or Woutreman van Ghent, in Dutch) – the family origins in Ghent are well documented. Woutreman van Ghent (1214–1261), was the youngest son of Zeger II, Viscount de Gand, himself grandson of William of Ypres, legitimated son of Phillip of Ypres and his concubine, madam of Loo.
- There is another version – less likely – that relates the Oultreman family with another family from the region, the Oultremont (or Houltremont) family.
Among their descendents in Portugal one can find:
- Alfredo Augusto das Neves Holtreman, 1st Viscount de Alvalade – founder of Sporting Clube de Portugal
- António Maria Holtreman do Rego Botelho de Faria, 1st Count do Rego Botelho
- António Luís (Holtreman)-Roquette Ricciardi – Patriarch and head of the Espirito Santo family
- Carlos Augusto Holtreman Franco - Guilhermina Suggia prize in 1966, Co-founder of the "Grupo de Música Contemporânea de Lisboa"
- João Maria Holtreman do Rego - Co-founder of the Portuguese Chemical Society
- João Lopes Holtreman - founder of the Portuguese Antiquarian Booksellers Association
- José Alfredo Holtreman-Roquette (José Alvalade) - founder of Sporting Clube de Portugal
- José Alfredo Parreira Holtreman-Roquette - well known businessman and former President of Sporting Clube de Portugal
- José Carlos Xavier Holtreman - Artist, Actor, and Writer
- Hugo (Holtreman-Roquette) Ricciardi O'Neill, the current head of the Clanaboy O'Neill dynasty - the senior branch of the High Kings of Ireland
- Victor de Oliveira Holtreman - Editor-in-Chief of ScreenRant.com, a popular movie news website that is visited over one million times a month
Nowadays, there are mainly two family branches holding the Holtreman name in Portugal: The Holtreman-Roquette branch, being the senior male representative José Alfredo Parreira Holtreman Roquette, and the Holtreman branch, being the senior male representative Victor de Oliveira Holtreman, born and living in the United States of America without male descendents. In Portugal, the eldest male representative of the latter branch - with male descendents - is João (John) Lopes Holtreman, Victor's uncle.