Jai Singh was born in 1688 in the Indian state of Rajasthan. His father, a maharaja in Amber, the capital of the Kachavaha clan of Rajputs, was under the authority of the Mogul powers in Delhi. The young prince was educated in such languages as Hindi, Sanskrit, Persian, and Arabic. He also received education in mathematics, astronomy, and the martial arts. But one subject was closest to the prince’s heart. A text of his times states: “Sawai Jai Singh from the first dawning of reason in his mind, and during its progress toward maturity, was entirely devoted to the study of mathematical science (astronomy).”
Jai Singh ascended the throne of Amber, following the death of his father. Soon the young king was called by the Mogul emperor to his court in south India, where Jai Singh met Jagannātha, a man well versed in mathematics and astronomy. This man later became the king’s principal assistant. The young maharaja’s political fortunes fluctuated until 1719, when the reign of Muḥammad Shāh began. Jai Singh was then called to the capital, Delhi, for a meeting with the new Mogul ruler. At this meeting, held in November 1720, Jai Singh apparently proposed the building of an observatory, which probably became a reality in 1724.
What motivated the maharaja to build an observatory? Jai Singh realized that the almanacs and astronomical charts in India were sadly inaccurate and that little progress was being made in the field of astronomy. So he decided to make new charts that would correspond to the actual visible heavenly bodies. He also had a desire to make instruments for astronomical observations available to every person devoted to the study of astronomy. Jai Singh thus acquired a vast library of books from France, England, Portugal, and Germany. In his court, he welcomed scholars from Hindu, Islamic, and European schools of astronomy. He even sent the first fact-finding mission from the East to Europe to collect information on astronomy, and he commissioned them to bring back books and instruments.