Upanishad Brahmayogin
Upanishad Brahmayogin is the cognomen of Rāmachandrendra Sarasvati (fl. 1800 CE), a sannyasin and Advaitin scholar of the Upanishads. He is credited with having written commentaries on all 108 Upanishads of the Muktika canon. His works have been translated and published by the Adyar Library. He was born Śivarāma of Vādhūla gotra in Brahmapuram, a village on the river Palar. This would date to the middle of the 18th century, based on tales of his association, as an older contemporary, with Tyagaraja (1767–1847 CE). He was initiated into Sannyasa by Vasudevendra Sarasvati in Kanchipuram, where he settled down , and eventually founded a matha of his own, the Upanishad Brahmendra matham. His initiation name was Rāmachandrendra, but he came to be known for his scholarship by names such as Upanishad-brahma-yogi, Upanishad-brahmendra and Upanishad-brahman. His commentaries on all 108 Upanishads of the Muktika canon were the fulfilment of a wish of his father Śivakāmeśvara. Besides these, he was also the author of independent works such as the "Paramādvaita-siddhānta-paribhāṣā" and the "Upeya-nāma-viveka". A prolific author, he annotated the colophons of each of his works with the number of granthas contained in it, presumably  to prevent interpolation. On this basis, his works amount to over 45,000 granthas. His samadhi is located on the banks of the Sarva Teertham tank in Kanchipuram along with 4 other Samadhis.