Two gothic parts constitute the name HOUDRY {1}: "hold" means gothic and "hari" means army. Its phonetic evolution is as follows {2,3,4}.
The roman prototype was "uldericus". The initial pretonic element disappeared and the popular roman form [*oldrikus] appeared. In the IVth century, the intervocalic [c] voiced and gave the form [*oldrigus]. It degenerated during the VIth century, [g] became a gamma and the tone of the final vowel became almost as "o": the form [*oldrigos] appeared. In the VIIth century, the final "o" was no longer audible in the form [*oldrigs]. In the IXth century, the final compound [gs] also disappeared and the name became as [*oldri]. Then the form evolved in [u(l)dri] by the vocalization of the velar "l" before the "d".
Genealogical searches have been conducted by the authors in the French area called "Brie des Morins" (approximately between the towns of Coulommiers and La Ferté-Gaucher in the departement of Seine-et-Marne near Paris). The old writing HOULDRY has been found in the oldest registers for the two following catholic parishes: St-Rémy-de-la-Vanne and Jouy-sur-Morin.
For this area at least, HOUDRY was (and is) always written with an initial H and a final Y. The initial H sometimes disappears eastwards or westwards. The final Y never disappears.