Sounds like a lot Jewish communities through the centuries. Most of them didn't suffer a very good fate.
Most of them fled to India when Iran was swamped by Islam.
http://www.haruth.com/AsianIndia.html
Who Are The Jews of India, And What Are Their Origins?
India has a legacy of four distinct Jewish groups: the Bene Israel, the Cochin Jews, the Sephardic Jews from Europe, and the "Baghdadis" from Iraq. Each group practiced important elements of Judaism and had active synagogues. The Sephardic rites predominate among Indian Jews.
One of the most important Jewish peoples of India are the Bene Israel ("Sons of Israel"), whose main population centers were Bombay, Calcutta, Old Delhi, and Ahmadabad. The native language of the Bene Israel was Marathi, while the Cochin Jews of southern India spoke Malayalam.
The Bene Israel claim to be descended from Jews who escaped persecution in Galilee in the 2nd century BCE. The Bene Israel resemble the non-Jewish Maratha people in appearance and customs, which indicates intermarriage between Jews and Indians. However, the Bene Israel maintained the practices of Jewish dietary laws, circumcision, and observation of Sabbath as a day of rest.
The Bene Israel say their ancestors were oil pressers in the Galil and they are descended from survivors of a shipwreck. In the 18th Century they were "discovered" by traders from Baghdad. At that time the Bnei Israel were practicing just a few outward forms of Judaism (which is how they were recognised) but had no scholars of their own. Teachers from Baghdad and Cochin taught them mainstream Judaism in the 18th and 19th centuries.
Jewish merchants from Europe travelled to India in the medieval period for purposes of trade, but it is not clear whether they formed permanent settlements in south Asia. Our first reliable evidence of Jews living in India comes from the early 11th century. It is certain that the first Jewish settlements were centered along the western coast. Abraham ibn Daud's 12th century reference to Jews of India is unfortunately vague, and we do not have further references to Indian Jews until several centuries later.
The first Jews in Cochin (southern India) were the so-called "Black Jews", who spoke the Malayalam tongue. The "Sephardic Jews" settled later, coming to India from western European nations such as Holland and Spain. A notable settlement of Spanish and Portuguese Jews starting in the 15th century was Goa, but this settlement eventually disappeared. In the 17th and 18th centuries, Cochin had an influx of Jewish settlers from the Middle East, North Africa, and Spain.
The Jews of Cochin say that they came to Cranganore (south-west coast of India) after the destruction of the Temple in 70ce. They had, in effect, their own principality for many centuries until a chieftanship dispute broke out between two brothers in the 15th century. The dispute led neighbouring princes to dispossess them. In 1524, the Moors, backed by the ruler of Calicut (today called Kozhikode) attacked the Jews of Cranganore on the pretext that they were "tampering" with the pepper trade. Most Jews fled to Cochin and went under the protection of the Hindu Raja there. He granted them a site for their own town which later acquired the name "Jew Town" (by which it is still known).
Unfortunately for the Jews of Cochin, the Portuguese occupied Cochin in this same period and indulged in persecution of the Jews until the Dutch displaced them in 1660. The Dutch protestants were tolerant and the Jews prospered. In 1795 Cochin passed into the British sphere of influence. In the 19th century, Cochin Jews lived in the towns of Cochin, Ernakulam, and Parur. Today most of Cochin's Jews have emigrated (principally to Israel).
16th and 17th century migrations created important settlements of Jews from Persia, Afghanistan, and Khorasan (Central Asia) in northern India and Kashmir. By the late 18th century, Bombay became the largest Jewish community in India. In Bombay were Bene Israel Jews as well as Iraqi and Persian Jews.
Near the end of the 18th century, a third group of Indian Jews appears. They are the middle-eastern Jews who came to India through trade. They established a trading network stretching from Aleppo to Baghdad to Basra to Surat/Bombay to Calcutta to Rangoon to Singapore to Hong Kong and eventually as fare as Kobe in Japan. There were strong family bonds amongst the traders in all these places.
Typical is the founder of the Calcutta community, Shalom Aharon Ovadiah HaCohen. He was born in Aleppo in 1762 and left in 1789. He arrived in Surat in 1792 and established himself there. He traded as far as Zanzibar. In 1798 he moved to Calcutta. In 1805 he was joined by his nephew, Moses Simon Duek HaCohen, who married his eldest daughter Lunah. Soon the community was swelled by other traders and Baghdadis outnumbered those from Aleppo.
Under British rule, the Jews of India achieved their maximum population and wealth, and the Calcutta community continued to grow and prosper and trade amongst all the cities of the far east and to the rest of the world. The Indians were very tolerant and the Jews of Calcutta felt completely at home. Their numbers reached a peak of about 5000 during WW-II when they were swelled by refugees fleeing the Japanese advance into Burma.
The first generations of Calcutta Jews spoke Judeo-Arabic at home, but by the 1890s English was the language of choice. After WWII, nationalism fever caught the Indians rather strongly and it became less comfortable for the Jews who came to be identified with the English by the Indians. India's Jewish population declined dramatically starting in the 1940s with heavy immigration to Israel, England, and the United States. It is in these 3 nations where the most significant settlements of Indian Jews exist today. Today there is just a handful of old people and the once vital community with its 3 synagogues is no more.
For more details, visit the Jews of Cochin Website (http://www.kashrus.org/asian/cochin.html).
Lastly, note that there were a number of European Jews who lived, or settled in India. Some examples: Lady Mountbatten, and Haffkine, after whom the famous Haffkine Institute in Bombay (Mumbai) has been named. The mother of one of India's most glamorous film actresses, Zeenat Aman is said to be Jewish.
Many Indian Jews have reached great prominence. For example, the Sassons after whom the Sasson docks, the Sasson hospital, and two of Mumbais well known sites- the Jacob Circle, and Flora Fountain have been named. In the past years, there has been a Jewish mayor of Bombay (Dr. E. Moses), and a Jewish Chief of the Navy. In the Indian Army, Jews have reached very high posts. A General Jacobs, now the Governor of Goa, supervised the surrender of the Pakistani Army in the Liberation of Bangladesh in 1971. Maj. Gen. Samson who was awarded the Padma Bhushan, and a few other Jews reached prominence in the Indian Army. Two of India's leading literary personalities, poet Nissim Ezeickel, and cartoonist Abu Abraham are Jewish. Also the late famous Hindi film actor David, and the late "Sulochana" the Queen of Indian Silent Films, and the actress/dancer Helen. A Dr. Erulkar was the personal physician/friend of Mahatma Gandhi. His father, also a Dr. Abraham Erulkar, donated land for the synagogue in Ahmedabad, Gujrat. Dr. Erulkar's daughter is currently the 1st lady of Cyprus, married to the President of Cyprus. Another prominent Indian Jew is Dr. Jerusha Jhirad, who was given the title of Padma Shri by the Government of India.
A good book on this subject is Nathan Katz's Who Are the Jews of India?. University of California Press, November 2000. Hardcover. ISBN: 0-520213-23-8
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