On June 4, 2007 signed a twinning agreement with the towns of Vouillé (department of Deux-Sèvres, Poitou-Charentes, France) and Tournai (Wallonia region, Belgium), to promote cultural exchanges and develop a cultural tour of Europe, on the occasion of the fifteenth centenary of the Battle of Vouillé. In that town near Poitiers, Clovis I, king of the Franks, defeated the Visigoths of Alaric II in 507. Tournai was the first capital of the Franks under kings Clovis and Childericus.
The name "Guadamur" (Arabic: قدمر) is believed by some scholars to come from an Arabic term meaning 'the river of the waves'. Others suggest that the word derives from wadi al-mur 'river of the wall', referring to a Roman Visigothic hydraulic engineering construction here: the resulting name under this hypothesis is a hybrid of Arabic word wadi, "river valley" and the Latin word murus, "wall". Wadi, (Arabic: الوادي), is a word of Arabic origin used to describe river valleys for much of the year dried up, but subject to dangerously sudden water surges.)