The Indian ascetic who accompanied Alexander’s army was Calanus, also spelled Kalanos. He was an Indian gymnosophist, or ascetic philosopher, associated with Taxila in the northwestern Indian subcontinent.
Calanus joined Alexander during the Macedonian campaign in India and traveled west with the army into the Persian territories. Ancient accounts describe him as a philosophical figure who attracted Alexander’s interest in Indian religious and intellectual traditions. His presence reflects the cultural encounters created by Alexander’s invasion of India in 326 BC.
Calanus later became seriously ill near Susa. In 323 BC, he chose to die by self-immolation on a funeral pyre in front of Alexander and the assembled army. Greek and Roman writers presented the event as an example of his ascetic beliefs and determination to control the manner of his death.
Dandamis is a common mix-up: he was another Indian ascetic whom Alexander met or sought out, but he did not accompany the army west. “Kalanos” is the closer transliteration of the name; “Calanus” is the established Latinized form used in many English historical works.