Pratinidhi Pant’s The Ten-Point Way to Health (1938), cover:
Pratinidhi Pant, the Rajah of Aundh (1868-1951), was the developer and promoter of the Surya-namas-kar (‘paying homage to the sun’), publishing a short manual and introduction in 1928 entitled: Surya Namaskars (Sun-Adoration) for Health, Efficiency & Longevity. In 1938 this first book was replaced by his The Ten-Point Way to Health, written effectively in collaboration with its editor the British journalist Louise Morgen and using his son Apa as the model in the photographs. The first work was directed exclusively to Indian men, the second to a wider audience including women and Westerners.
It appears that all fluid, moving asana practice ultimately depends on this development. For Pant the sun salutes themselves were not regarded as ‘yoga’.
The antecedents are unclear. There is an elaborate practice of bowing to the sun practiced (only) by Brahmins and as a religious ritual, but it was in no sense a form of physical culture or exercise and had no connection to yoga. There were also training drills of some kind in use in what is now the Indian state of Maharashtra from the 17th century on that were at least regarded as related to the modern sun salute. One clear influence was the international physical culture movement that developed in the 19th century West, often with a nationalistic rationale. This took on a particular imperative in India: building the Indian body (and will) to throw off the British yoke.
In the pre-modern haṭha yoga texts (which admittedly bear an uncertain relation to practice) āsana are never conjoined into sequences. In contemporary ‘non-modern’ haṭha practice, sādhus (‘sages’) may do “a few minutes of asana” before sitting in meditation, which does suggest something adaptable and moving. But for those who devote themselves to āsana as their mode of practice (now a minority: it is the guru who decides what the student will do), the poses are performed not only singly but are actually mastered one by one: only once the student has perfected a pose does he (almost always he) move on to the next one. (From ethnographic fieldwork by Daniela Bevilacqua, lecture available here.)
Page from M. R. Jambunathan’s The Yoga Body Illustrated of 1935 (YAT catalogue 26F):
Sunsalutes for massed youth in pre-independance India:
First two images above are taken from Yoga: the Art of Transformation (Debra Diamond/Smithsonian Institution 2013), catalogue 26D and F. Much of the information below is from the very full history of the sun salute provided by Elliott Goldberg in Part 2 of his The Path of Modern Yoga: The History of an embodied Spiritual Practice (2016), which is the source of the third and final image just above.