The three earliest manuscripts which do survive of the Latin Martyrologium Hieronymianum as such are all relatively late, from the 8th century, which means they have inevitably suffered interference in the course of transmission. The oldest of them[5] comes from the monastery of the Northumbrian missionary St Willibrord at Echternach and was written in England in the first years of the 8th century. Two other important manuscripts were written in the same century, one for the monastery of Saint Avoldus near Metz,[6] and the other was copied by 772 AD for the monastery of Saint-Wandrille and then came to the monastery of St Peter in Wissembourg.

Echternach – Wikipedia

https://en.wikipedia.org/wiki/Echternach

Echternach (Luxembourgish: Iechternach [ˈiəɕtɐnɑχ] (listen) or (locally) Eechternoach) is a commune with town status in the canton of Echternach, which is part of the district of Grevenmacher, in eastern Luxembourg. Echternach lies near the border with Germany, and is the oldest town (current population 5,610) in Luxembourg.