The First Prime Meridian (Madhyarekha) – The Greenwich of the East

The Concept The world had a zero meridian long before Greenwich. The Surya Siddhanta created the Madhyarekha, a line that connects the North Pole (Mount Meru) with the observatory city of Ujjain and ‘Lanka’ on the equator. Ujjain Mean Time was used to determine the positions of all planets. Astronomers employed Desantara, a mathematical correction based on how far east or west the observer was from this line, to calculate local time.

The Story Long before Greenwich, England, became the center of the world’s maps in 1884, there was Ujjain. Known as the “Greenwich of the East,” this Indian city sat exactly on the Madhyarekha—the world’s first Prime Meridian. Ancient astronomers used Ujjain as the “Zero Point” to synchronize clocks and calculate planetary positions across the entire continent. They even developed a mathematical correction called Desantara to adjust time for travelers moving east or west of this line. It was a global grid system established thousands of years before the first European explorers ever set sail.

The Timeline

The Original Text

Sanskrit Shloka: राक्षसालयमारभ्य लंकां हित्वा स्वलंकृताम् । उज्जयिनीं च कुरुक्षेत्रं च मेरुं गता रेखानिरक्षदेशा ॥

Transliteration: Rākṣasālayamārabhya laṅkāṃ hitvā svalaṅkṛtām | Ujjayinīṃ ca kurukṣetraṃ ca meruṃ gatā rekhānirakṣadeśā || Surya Siddhanta (1.62)

Meaning: “Starting from the abode of the Rakshasas (Lanka), passing through the beautiful city of Ujjain, Kurukshetra, and reaching Mount Meru—this line is the Prime Meridian (Madhyarekha).”

 

Related Innovations Setting the 0° Latitude/Longitude point where the equator and meridian intersect. Source: Surya Siddhanta.

Fun Fact Did you know that the ancient city of Ujjain is located almost exactly at the Tropic of Cancer? This meant that the Sun passed directly over it on the Summer Solstice.

The Modern Legacy This is the ancestor of Geodesy and GPS, the grid system that helps you to locate any point on Earth.