Carrots originated in the Himalayas and Hindu Kush center of the continent and moved in both directions on the Silk Road, an ancient network of trade routes, formally established during the Han Dynasty of China, which linked the regions of the ancient world in commerce between 130 BCE-1453 CE.
It is generally assumed that the eastern, purple-rooted carrot originated in Afghanistan in the region where the Himalayan and Hindu Kush mountains meet, and that it was domesticated in Afghanistan and adjacent regions of Russia, Iran, India, Pakistan and Anatolia. Purple carrot, together with a yellow variant, spread to the Mediterranean region and western Europe in the 11–14th centuries, and to China, India and Japan in the 14–17th centuries.
The discovery of a purple carrot attracted more interest from international traders. Traders carried purple carrots south to India and west to Baghdad, then to Spain, and then to the rest of Europe by 1000 AD. People did more experimenting. By the 1000s, people were breeding red and yellow carrots in West Asia, and they had reached Spain by the 1100s, about the same time as lemons. Kublai Khan brought carrots east to China about 1300 AD.
The cultivated carrot is believed to have originated from forms with roots colored purple anthocyanins as well as yellow mutants lacking anthocyanins. These forms spread to the West and East reaching Asia Minor around the 10th or 11th centuries, Arab occupied Spain in the 12th century, continental North West Europe by the 14th century. England in the early 15th century. Before the 16th century carrots were purple or yellow with long roots. The yellow roots were often preferred because they did not release anthocyanins during cooking. In the 16th century it is thought that Dutch growers developed a denser orange carotene carrot from yellow varieties and this deep orange carrot was the progenitor of the modern cultivated carrot we know.
The first evidence of carrot used as a food crop is in the Iranian Plateau and the Persian Empire in the 10th century AD (Brothwell & Brothwell 1969). These original carrot roots were purple and yellow in color. From Persia, cultivated carrot spread to surrounding areas. Orange carrots appear to have become popular in the 16th century when Dutch and Spanish paintings began depicting orange carrots in market scenes (Banga 1963), although orange carrots likely originated much earlier (Stolarczyk & Janick 2011). Banga (1957) first hypothesized that orange carrots were initially selected from yellow cultivars and this is now supported by modern genetic analyses (Simon et al 2016).
The western, orange carrot probably arose in Europe or in the western Mediterranean region through gradual selection within yellow carrot populations. The Dutch landraces Long Orange and the finer Horn types, first described in 1721, were an important basis for the western carrot cultivars grown at present all over the world.