Santiago, (also San Tiago, Santyago, Sant-Yago, San Thiago) is a Spanish name that derives from the Hebrew name Jacob (Ya'akov) via "Sant Iago", first used to denote Saint James the Great, the brother of John the Apostle. It was also the tradition that Saint James (Santiago) had traveled to the Iberian Peninsula during his life and was buried there. The name is also complicated in Spanish in that Jaime is a modern version of James; and another variant is Diego, as in San Diego, as a doublet or variation.
Variants of Santiago include the surname Sandiego, and (after removing the "san" particle which means "Saint" in Spanish) Thiago or Tiago (a common Portuguese language name), Diego, and the less common Diago and Diogo. The common name James has many forms in Iberia, including Jaúme, Xaúme, and Diego (in Catalá), and Jaime and Diego (in Spanish). However, despite being a cognate, San Diego does not refer to the same Saint but to Saint Didacus.
San Diego is one of the Hispanicized forms of James, originating from the name Santiago. It is original name of Didacus of Alcalá. One should note the name Didacus did exist as a big umbrella until Diego / Diago was "Latinized." For more information see Diego article.
