Constantine II (circa 1100 – 1163) was the giudice of Cagliari (as Salusio III from circa 1129). He was called de Pluminus after his capital city. He was the only son of Torchitorio II. From his youth he was associated as co-ruler with his father. He first bears the title iudex Caralitanus in a document of 13 February 1130 in which he confirmed certain donations of his father in Pisa. As it was traditional for a giudice to begin his reign by confirm some grant of his predecessor's, this 1130 confirmation probably indicates that Constantine's reign began just before that date.