The Jews of India aren't one singular community. Among themselves they are
divided into different communities. Each community has its own different
culture, background and origin. Each community claims its arrival in India in
different ways and it is not always clear how they really came to India. The
three main Jewish communities of India are: Bene Israel, Cochini and Baghdadi.
Besides there were Ashkenazi Jews and a community in east India which claim
Israeli origin and call themselves Bne Menashe. The first three communities had
some social religious connections with each other but most of the social
religious connections of each community were within their own community and they
regarded the other as "outsiders".
Trade contacts between the Mediterranean region and the west coast of India probably led to the presence of small Jewish settlements in India as long ago as the early first millennium B.C. In Kerala a community of Jews tracing its origin to the fall of Jerusalem in A.D. 70 has remained associated with the cities of Cranganore and Kochi (formerly known as Cochin) for at least 1,000 years. The Pardesi Synagogue in Kochi, rebuilt in 1568, is in the architectural style of Kerala but preserves the archaic ritual style of the Sephardic rite, with Babylonian and Yemenite influence as well. The Jews of Kochi, concentrated mostly in the old "Jew Town," were completely integrated into local culture, speaking Malayalam and taking local names while preserving their knowledge of Hebrew and contacts with Southwest Asia. A separate community of Jews, called the Bene Israel, had lived along the Konkan Coast in and around Bombay, Pune, and Ahmadabad for almost 2,000 years. Unlike the Kochi Jews, they became a village-based society and maintained little contact with other Jewish communities. They always remained within the orthodox Jewish fold, practicing the Sephardic rite without rabbis, with the synagogue as the center of religious and cultural life. A third group of Jews immigrated to India, beginning at the end of the eighteenth century, following the trade contacts established by the British Empire. These Baghdad Jews came mostly from the area of modern Iraq and settled in Bombay and Calcutta, where many of them became wealthy and participated in the economic leadership of these growing cities.
The population of the Kochi Jews, always small, had decreased from 5,000 in 1951 to about fifty in the early 1990s. During the same period, the Bene Israel decreased from about 20,000 to 5,000, while the Baghdad Jews declined from 5,000 to 250. Emigration to Australia, Israel, Britain, and North America accounts for most of this decline. According to the 1981 Indian census, there were 5,618 Jews in India, down from 5,825 in 1971. The 1991 census showed a further decline to 5,271, most of whom lived in Maharashtra and Mizoram.