The Lusitanians (or ) were an Indo-European people living in the west of the Iberian Peninsula prior to its conquest by the Roman Republic and the subsequent incorporation of the territory into the Roman province of Lusitania (most of modern Portugal, Extremadura and a small part of the province of Salamanca). The Lusitanians are often reckoned to have spoken the Lusitanian language, an Indo-European language influenced by a Celtic superstrate. However, a group of scholars has contended that the language is a form of Celtic or para-Celtic that evolved alongside Celtic, to which was added the more recent theory that the Celtic languages originated in Iberia, also based on the hypothesis of the Lusitanian language as a form of para-Celtic (among other theoretical cases on other languages).