Historically the brassicas are one of the earliest domesticated crop plants by man. It is mentioned in several ancient scripture and literature and might have been cultivated as early as 5000 BC. There is evidence of its cultivation in Neolithic age (Chang 1968). Seeds of mustard were found from the Channhu- daro of Harrapan civilization ca. 2300-1750 BC (Allchin 1969). Aryans used Brassica species as condiments and for oil. However, the use of oil was still commoner with the non-Aryans than the Aryans. Thus it is evident that in a period of over 3500 years, mustard came to occupy an important place in the diets of Indian people as a source of oil and vegetable.
The origin of B. juncea is conflicting. Middle East seems to be the place of origin since the putative parent species; B. nigra and B. campestris would have crossed. (Olson 1960, Mizushima and Tsunoda 1967). From there it soon spread to Europe, Africa, Asia, India and Far-East (Hemingway, 1976). It had arisen more than once with different progenitors and in different localities i.e., China, Eastern India and the Caucasus the present day two centers of diversity (Hemmingway 1976, Prakash and Hinata 1980). Biochemical and molecular studies support this finding and further provide evidence for the existence of two geographical races, Chinese and Indian (Vaughan et al.1963, Vaughan and Gordon 1973, Song et al 1988).
The Brassicaceae, contains about 3500 species and 350 genera, is one of the 10 most economically important plant families (Warwick et al 2000). It is distinguished on the basis of the presence of conduplicate cotyledons (i.e. the cotyledons are longitudinally folded around the radical) and/ or two-segmented fruits (siliquae), which contain seeds in one or both segments, and only simple hairs, if present. Crop Brassicas encompass many diverse types of plants, which are grown as vegetables, fodder or sources of oils and condiments.The oleiferous Brassica species, commonly known as rapeseed-mustard, are one of the economically important agricultural commodities. Rapeseed-mustard comprising eight different species viz. Indian mustard, toria, yellow sarson, brown sarson, gobhi sarson, karan rai, black mustard and taramira, are being cultivated in 53 countries spreading all over the globe .

The genus Brassica has mainly a Mediterranean distribution, but it expands to Africa and Asia; including India. The distribution of the cultivated species is as follows:
B. nigra. This species was cultivated as a spice as early as 3000 BC. Although it may originate in Asia Minor-Iran, it is now widespread through out Europe, Africa, Asia, India and the Far East (Hemingway 1979).
B. oleracea. Wild forms of this species are found in Northern France and England. Related species are endemic of the Mediterranean basin. A great array of different crops have been domesticated in various western European regions, such as Greece and Rome where some of these crops might have cultivated since the 1st century AD (Sauer 1993).
B. rapa (syn. campestis). Wild forms are found in Western Europe, western USSR, Afghanistan, Pakistan, Asia, Transcaucasus and Iran (Mc Naughton 1979). This species has been domesticated as different crops in different regions; turnips in Europe, leafy vegetables in China and Japan and oil types in India, Central Asia and Afghanistan. Oilseed type sarson was cultivated in India as early as 1500 BC (Sauer 1993). Different forms of this species might have been cultivated as roots and vegetables as early as 5000 BC in China (Li 1983). B. carinata. It is found and cultivated in north eastern Africa and Ethiopia in particular, where it is sympatric with B. nigra and cultivated kales (B. oleracea).
B. juncea. Central Asia-Himalayas are a primary center of diversity for this species, with migration to China, India and the Caucasus (Hemingway (1979). Perhaps it is the oldest of the cultivated amphidiploids, it is mentioned since ancient times. B. juncea is grown for oil-seed usage in India and presently gaining importance in Canada and USA as an alternative to rapeseed i.e. B. napus.
B. napus. This species seems to be of relatively recent origin, and the South West and Mediterranean regions are the areas of diversity.

The estimated area, production and yield of rapeseed-mustard in the world was 36.59 million hectares (mha), 72.37 million tonnes (mt) and 1980 kg / ha, respectively, during 2018-19 (Fig.1). Globally, India account for 19.8 % and 9.8% of the total acreage and production (USDA). During the last eight years, there has been a considerable increase in productivity from 1840 kg/ha in 2010-11 to 1980 kg/ha in 2018-19 and production has also increased from 61.64 m t in 2010-11 to 72.42 m t in 2018-19.

Rapeseed–mustard crops in India are grown in diverse agro climatic conditions ranging from north-eastern / north western hills to down south under irrigated/rainfed, timely/late sown, saline soils and mixed cropping. Indian mustard accounts for about 75-80 % of the 6.23 m ha under these crops in the country during 2018-19 crop season.

Soybean, groundnut and rapeseed-mustard are the major oilseed crops in India contributing nearly 84% and 88% to its total acreage and production, respectively(Average of 2014-15 to 2018-19).