[1][2] The Diocese of Sulci was an episcopal seat as early as the seventh century.

After its decline the bishop of Sulci took up his residence at the village of Tratalias.

[3] In 1503, the seat was officially moved to Iglesias but, in 1514, the Diocese was reunited with the Archdiocese of Cagliari.

[citation needed] The cathedral of Iglesias (then Villa di Chiesa) was erected by the Pisans in 1285, but has been restored in later times.

[4] The previous cathedral located in Tratalias was built in a Pisan Romanesque style between 1213 and 1282.