Chili peppers have been a part of the human diet in the Americas since at least 7500 BC. There is archaeological evidence at sites located in southwestern Ecuador that chili peppers were domesticated more than 6000 years ago, and were one of the first self-pollinating crops cultivated in Central and South America.
Christopher Columbus was one of the first Europeans to encounter them (in the Caribbean), and called them "peppers" because they, like black and white pepper of the Piper genus known in Europe, have a spicy hot taste unlike other foodstuffs. Upon their introduction into Europe, chilis were grown as botanical curiosities in the gardens of Spanish and Portuguese monasteries. But the monks experimented with the chili culinary potential and discovered that their pungency offered a substitute for black peppercorns, which at the time were so costly that they were used as legal currency in some countries.
Chilies were cultivated around the globe after Columbus. Diego Álvarez Chanca, a physician on Columbus' second voyage to the West Indies in 1493, brought the first chili peppers to Spain and first wrote about their medicinal effects in 1494.
The spread of chili peppers to Asia was most likely a natural consequence of its introduction to Portuguese traders (Lisbon was a common port of call for Spanish ships sailing to and from the Americas) who, aware of its trade value, would have likely promoted its commerce in the Asian spice trade routes then dominated by Portuguese and Arab traders.
There is a verifiable correlation between the chili pepper geographical dissemination and consumption in Asia and the presence of Portuguese traders, India and southeast Asia being obvious examples.
The chili pepper features heavily in the cuisine of the Goan region of India, which was the site of a Portuguese colony (e.g., vindaloo, an Indian interpretation of a Portuguese dish). Chili peppers journeyed from India, through Central Asia and Turkey, to Hungary, where it became the national spice in the form of paprika.
An alternate, although not so plausible account (no obvious correlation between its dissemination in Asia and Spanish presence or trade routes), defended mostly by Spanish historians was that from Mexico, at the time a Spanish colony, chili peppers spread into their other colony the Philippines and from there to India, China, Indonesia. To Japan, it was brought by the Portuguese missionaries in 1542, and then later, it was brought to Korea.
In 1995 archaeobotanist Hakon Hjelmqvist published an article in Svensk Botanisk Tidskrift claiming there was evidence for the presence of chili peppers in Europe in pre-Columbian times. According to Hjelmqvist, archaeologists at a dig in St Botulf in Lund found a Capsicum frutescens in a layer from the 13th century. Hjelmqvist thought it came from Asia. Hjelmqvist also said that Capsicum was described by the Greek Theophrastus (370–286 BCE) in his Historia Plantarum, and in other sources. Around the first century CE, the Roman poet Martialis (Martial) mentioned "Piperve crudum" (raw pepper) in Liber XI, XVIII, allegedly describing them as long and containing seeds (a description which seems to fit chili peppers - but could also fit the long pepper, which was well known to ancient Romans).