Mahendra Sūri (c. 1340 – 1400)^[1] is the 14th centuryJainastronomer who wrote theYantraraja, the firstIndian treatise on theastrolabe.^[2] He was trained by Madana Sūri, and was teacher to Malayendu Sūri.^[1]Jainism had a strong influence on mathematics particularly in the last couple of centuries BC. By the time of Mahendra Suri, however, Jainism had lost support as a national religion and was much less vigorous.

Mahendra Suri's fame rests on the workYantrarāja, which introduced the astrolabe to the Indian astronomer.^[1] Mahendra Sūri was patronized by theTughluq ruler of Delhi,Firūz Shāh (r. 1351–1388), who evinced keen interest in astronomy. Firūz Shāh had earlier caused theBṛhatsaṃhitā of Varāhamihira to be translated intoPersian. At the sultan's instance, Mahendra Sūri studied the astrolabe and introduced it to the Sanskrit audience in 1370 in hisYantrarāja. Its circulation was largely, if not wholly, confined to astronomers who worked within the Islamic and Ptolemaic traditions.^[1][3][4][5]

TheYantrarāja is best described as anastrolabe user's manual. It explains how this king (rāja) of instruments (yantra) is to be constructed and commissioned for purposes of observation. Thesaumyayantra (northern instrument) projected from theSouth Pole and theyāmyayantra (southern instrument) projected from the North Pole are discussed separately, followed by a description of thephaṇīndrayantra (the serpentine instrument), which combines both.^[1][3][4][5]

A detailed discussion on the application of the astrolabe is found in Malayendu Sūri's commentary on theYantrarāja. This commentary is also interesting because it provided, for the first time to Indian astronomers, tables for ready reference, which helped simplify calculations. The commentator gave latitudes of 75 cities. Malayendu made a list of latitudes for 32 stars, which were identified as relevant for purposes of calculations in India.^[1][3][4][5]

• Indian mathematicians
• Yantraraja

• K. V. Sarma (2008), "Mahendra Suri",Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition) edited byHelaine Selin, Springer,ISBN 978-1-4020-4559-2.

• 14th-century Indian astronomers
• 14th-century Indian mathematicians
• 14th-century Indian Jains

• CS1 maint: multiple names: authors list
• Articles with short description
• Short description is different from Wikidata
• Use dmy dates from September 2019
• Year of death unknown
• Year of birth unknown
• Year of birth uncertain