This is a surname of pre 7th century Gallic origins. That is to say that it is from the original country known as Gaul, which encompassed parts of modern France, Flanders, and Germany. In France the surname is apparently recorded in the region of Alsace-Lorraine. This was for many centuries an area in continual dispute between France and Germany, being lost to France in the Prussian War of 1870, and not recovered until 1918. In the 19th century it was estimated that over 80% of the population were of Germanic origin, and to most residents German was their natural language. The surname as Ruous and the more popular Ruoss, is well recorded in Germany and specifically the former state of Wuerttemburg. The ultimate derivation being from the German surname Ruosch, itself a dialectal form of the original personal name 'Rolf'. This original personal name and later surname, translates as "Renowned wolf". In ancient times the wolf was renowned for its ferocity and cunning, and many early European (sur)names have an association with this animal. Examples of the surname taken from early surviving registers include: Jerg Ruoss of Donaukreis, on January 22nd 1559, and Joannes Georgius Ruos, of Jettenhausen, both Wuerttemburg.