You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Portugal

Context:
The Portuguese language is derived from the Latin spoken by the romanized Pre-Roman peoples of the Iberian Peninsula around 2000 years ago—particularly the Celts, Tartessians, Lusitanians and Iberians. In the 15th and 16th centuries, the language spread worldwide as Portugal established a colonial and commercial empire between 1415 and 1999. Portuguese is now spoken as a native language in five different continents, with Brazil accounting for the largest number of native Portuguese speakers of any country (200 million speakers in 2012).

Question:
By what group of people is Portuguese derived?

Pre-Roman peoples of the Iberian Peninsula