Ruy

Medieval Portuguese and Spanish short form of RODRIGO. It is another name of the 11th-century Spanish military commander Rodrigo Díaz de Vivar, also known as El Cid.

RODRIGO   male   Spanish, Portuguese, Italian, Galician
Spanish, Portuguese and Italian form of RODERICK. A notable bearer was Rodrigo Díaz de Vivar, also known as El Cid, an 11th-century Spanish military commander.
RODERICK   male   English, Scottish, Welsh
Means "famous power" from the Germanic elements hrod "fame" and ric "power". This name was in use among the Visigoths; it was borne by their last king (also known as Rodrigo), who died fighting the Muslim invaders of Spain in the 8th century. It also had cognates in Old Norse and West Germanic, and Scandinavian settlers and Normans introduced it to England, though it died out after the Middle Ages. It was revived in the English-speaking world by Sir Walter Scott's poem 'The Vision of Don Roderick' (1811).
FULL FORMS
PORTUGUESE: Rodrigo
SPANISH: Rodrigo
EQUIVALENTS
ANCIENT GERMANIC: Hroderich
CATALAN: Roderic
ENGLISH: Rod, Roddy, Roderick
FRENCH: Rodrigue
GALICIAN: Rodrigo, Roi
ITALIAN: Rodrigo
PORTUGUESE: Rui, Ruy
SPANISH: Ruy