Aydius is located some 25 km south by south-east of Oloron-Sainte-Marie just east of Bedous. Access to the commune is by the D237 road from Bedous which goes to the village and terminates there. The commune is alpine in nature with extensive forests, rugged terrain and snow-capped mountains in the east.

The Gabarret river rises in the east of the commune and flows west gathering a large number of tributaries including the Ruisseau d'Arces, the Ruisseau du Saslars, the Gave de Béranfueil, the Gave de Bouren, the Ruisseau d'Ilhiec, the Ruisseau Sarité, the Ruisseau de Traillère, and the Ruisseau de Sahun (which forms part of the western border of the commune) before flowing west to join the Gave d'Aspe at Bedous.

The commune name in Gascon is Aidius. Michel Grosclaude said that the name probably comes from the same root as Aydie but its origin and meaning remain obscure.

The following table details the origins of the commune name and other names in the commune.

Sources:

• Grosclaude: Toponymic Dictionary of communes, Béarn, 2006 (in French)
• Raymond: Topographic Dictionary of the Department of Basses-Pyrenees, 1863, on the page numbers indicated in the table. (in French)
• Cassini: Cassini Map from 1750

Origins:

• Census: Census of Béarn

A rock shelter dating from prehistory called Abri Gandon-Lassus has been discovered in the commune.

Paul Raymond noted on page 18 of his 1863 dictionary that the commune had a Lay Abbey, vassal of the Viscounts of Béarn and that in 1385 there were 30 fires and Aydius depended on the bailiwick of Aspe.

This list is incomplete; you can help by adding missing items. (April 2021)

List of Successive Mayors

The commune is part of four inter-communal structures:

• the Communauté de communes du Haut Béarn;
• the Energy association of Pyrénées-Atlantiques;
• the inter-communal association for aid to education in the Vallée d'Aspe;
• the joint association for Haut-Béarn.

In 2017 the commune had 114 inhabitants.

Historical population

Year Pop. ±% p.a. 1793 685 —     1800 726 +0.83% 1806 701 −0.58% 1821 891 +1.61% 1831 847 −0.51% 1836 822 −0.60% 1841 833 +0.27% 1846 890 +1.33% 1851 813 −1.79% 1856 855 +1.01% 1861 735 −2.98% 1866 695 −1.11% 1872 715 +0.47% 1876 694 −0.74% 1881 613 −2.45% 1886 586 −0.90% 1891 541 −1.59% 1896 526 −0.56%	Year Pop. ±% p.a. 1901 520 −0.23% 1906 518 −0.08% 1911 489 −1.15% 1921 349 −3.32% 1926 283 −4.11% 1931 268 −1.08% 1936 241 −2.10% 1946 181 −2.82% 1954 137 −3.42% 1962 98 −4.10% 1968 88 −1.78% 1975 94 +0.95% 1982 67 −4.72% 1990 74 +1.25% 1999 80 +0.87% 2007 102 +3.08% 2012 98 −0.80% 2017 114 +3.07%
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Source: EHESS and INSEE

The economy of the commune is mainly focused towards agriculture and livestock. The commune is part of the Appellation d'origine contrôlée (AOC) zone of Ossau-iraty.

The commune has many sites that are registered as historical monuments:

• The Maison Guiraudé (1891)
• The Maison Pualet (16th century)
• The Maison Hontas (18th century)
• The Abri Gandon-Lassus Prehistoric Cave (Prehistory)
• The Maison Ichante (1807)
• The Maison Casaubon (18th century)

• The Parish Church of Saint Martin (14th century) is registered as an historical monument.

Aydie contains a number of high mountains:

• The Sommet de Tachat (1,408 metres),
• The Sommet de Talabot (1,591 metres),
• The Sommet de Pétraube (1,606 metres,
• The Sommet de Houndarete (1,695 metres),
• The Soum de la Mousquère (1,778 metres,
• The Turon de la Goaita (1,805 metres,
• The Lousquette de Barca (1,870 metres,
• The Pic de Lariou (1,903 metres, and
• The Mailh Bassibe (1,973 metres.

• Communes of the Pyrénées-Atlantiques department

In his book L'ours et les brebis (The Bear and the sheep), Etienne Lamazou recounted his life as a transhumant shepherd from 1913 to 1969. Originally from Aydius, he never left except to take his cattle to their winter plain. He recounted the life of a shepherd as it still existed at the beginning of the 20th century. All the action takes place in and around Aydius and the book has many thousands of anecdotes sometimes soothing, sometimes moving, and often instructive.

Wikimedia Commons has media related to Aydius.

• Aydius on the 1750 Cassini Map