Paul Raymond mentions[4] the Haïçaguerry, a tributary of the Nivelle, which descended to Gorospila on the Spanish border, and which crossed the territory of Ainhoue (the old spelling of Ainhoa).

Military clashes between the "English run" Basques of Aquitaine and the Navarrese in 1249 led the Seigneur of Ainhoa, in 1250, to recognize the suzerainty of King Henry III of England.

Then, Garda Arnaut de Espelette, with loyalty to the "English run" Basques of the Duchy of Aquitaine, sent a letter, dated 29 July 1289 praying the Ainhoa people to adequately connive with him.

The outcome of such frontier business was to set up an "undivided" land as had been done also previously with the nearby Aldudes close to the Baztan valley.

Documents from Estella dated September 1369, some 80 years later, proved that the people from Ainhoa paid taxes to both the King of Navarre and the "English" Seneschal of the Landes territory in return for their fiscal and personal privileges.

Disputes between the new settlers and the old residents concerning the use of communal lands for cattle grazing and fodder and the access by newcomers to town hall positions, schooling, church grants, etc.

This resulted in the creation of the department of Basses-Pyrénées and reuniting the Béarn, the Gascon lands of Bayonne and Bidache, and the three French Basque provinces.

So Ainhoa was called Mendiarte, Ustaritz became Marat-sur-Nive, Itxassou became Union, Arbonne became Constante, Saint-Étienne-de-Baïgorry became Thermopyles, Saint-Palais became Mont-Bidouze, Louhossoa became Montagne-sur-Nive, Saint-Jean-Pied-de-Port became Nive-Franche, Saint-Jean-de-Luz became Chauvin-Dragon (the name of a young soldier killed in action), and Souraïde became Mendialde.

The Departments where people from the communes were interned were the Lot, the Lot-et-Garonne, the Gers, the Landes, the Basses-Pyrénées (partly béarnaise), and Hautes-Pyrénées.

The return of exiles and the recovery of their possessions were determined by a series of decrees issued on 29 September and 1 October 1794, driven in this direction by the Director of Ustaritz who said: "The onetime communes of Sare, Itxassou, Ascain, Biriatou, and Serres, whose inhabitants were interned eight months ago as a measure of general safety, have not been improved.

The people who come to obtain freedom to retire to their homes, clamour for food without my being able to procure the means to meet this primary human need, hunger.".

[17] The recovery of their possessions was not without difficulty, they were placed in receivership but were not registered and were looted: "The property, movable and immovable, of the inhabitants of Sare, were neither recorded nor legally described, and all our furniture and household effects were removed and brought confusedly to neighbouring communes.

[24] The weaving of flax (tisserands) and wool (duranguiers) persists in Ainhoa where in Hasparren it was an important activity until the advent of the textile industry in the 19th century.

[25] Philippe Veyrin[26] noted the existence of a factory making "chahako", small goatskins from male goats which peasants use for work or hunting.

The village is laid out as a fortified town, with concealed labourdine houses from the 17th century and a fronton open square against the cemetery surrounding the church.