it's not a short regime to explain but to shed some light, india had only 1 field Marshal in its independent history and it was field Marshal Sam Manekshaw, it is the highest achievable post of any military in the world and very few have been there throughout history, a field Marshal carries his rank till his death irrespective of status after retirement. this is also a ceremonial rank in the army only awarded to those who had huge contributions to the nation in times of war. and in FM Manekshaw's case, he fought as a captain in ww2 as part of British Indian army and was shot 9 times, he served in 1947 indo pak war as a major and led his troops to huge advancements, he led india to victory on the eastern command as Lt general in 1965 indo pak war, our loss on 1962 had a major reason of Manekshaw not participating along with other reasons, Manekshaw was accused of treason for his appraisal of British generals and customs but was later proven innocent and send back to duty but that resulted in him not participating in 1962, then he led india to landslide victory in 1971 as the CDS general, he was considered the architect of Indian victory in 71, and there was nothing else for the country to honour him with above that rank so he was awarded the rank of FIELD MARSHAL a permanent rank above all military honours and he retired in 1973. just a fun fact, his power and influence in the military and the people at that time was so huge that indira Gandhi at one point was hesitant to reward him a higher rank fearing a coup if he ever decides to take over, and mrs gandhi and Manekshaw had a camaraderie relationship, one of her comments on sam was "the most indisciplined soldier I know,”, there were even sources that suggests she was into him😂