Sawai Jai Singh II, the Kachwaha ruler of Amer, founded Jaipur in 1727. He was a renowned astronomer and city planner who designed Jaipur based on Vastu Shastra principles. The city was named after him. Sawai Madho Singh was a later ruler of Jaipur, while Rattan Singh and Jairattan Singh were not associated with founding the city.