Relations between India and Iran have been close and at times, strained. There have been many movements of people overland between these two countries, the most prominent is the Zoroastrian community's migration to western India due to their fear of spread of the message of Islam.
Between the late 19th and early 20th centuries, many wealthy Parsis, began to travel to Iran from Bombay and Gujarat, to revive the Zoroastrian faith and traditions among the stagnating Zoroastrian community in Iran at the time, with prominent personalities such as civil rights activist, Manekji Limji Hateria of Surat gaining local renown.
In 1920s, about 180 Indian families went to Zahidan. Following this initial influx, some of them started settling down in the nearby towns of Birijand, Zabol and Mashhad. In 1950s, more Indians migrated to Iran and settled primarily in Tehran. They consisted of Sikhs and Gujaratis. In the 1960s and early 1970s, about 10,000 Indian doctors, engineers, and teachers moved to Iran as a response to the open policies initiated by the Shah of Iran, but most of them left Iran after the Iranian revolution.
Now, there are several hundred people each concentrated in and around Tehran and Zahidan, primarily engaged in various small businesses. A majority are still Indian citizens. They continue to maintain strong links with India, especially in matters of children's education, marriage and property acquisition.