Swami Sri Yukteswar Giri was the Guru of Paramahansa Yogananda who was a pioneer for spreading Kriya Yoga in the west and well known as the author of the classic book 'Autobiography of a Yogi'.
Sri Yukteswar took birth on 10th May, 1855, as Priya Nath Karar in Serampore near Calcutta, India. He was the only son of Kshetranah and Kadambini Karar.
From the childhood, Praya nath was interesting in pursuing higher truths. He did not believe much in formal education and so his academic training was not extensive.
He had to take charge of their family land holdings early in his life after his father expired. He was married but his wife died just a few years after. Their only daughter also passed away young. Probably these developments in his life would have encouraged him further in his search for truth and he became a disciple of Lahiri Mahasaya of Banaras, who was the first to bring Kriya Yoga to the world in the modern age. Through the guidance of Lahiri Mahasaya and the practice of Kriya Yoga, Praya Nath Karar achieved higher spiritual states.
Priya Nath Karar realized that the blending of spiritual heritage of the East with the science and technology of the West would help the humanity to reduce the suffering in the modern world. In 1894, when he went to attend Kumbh Mela, a saint addressed him with the words 'Swamiji' though he was not a swami at that time. That saint was Babaji who appreciated his interest in bringing together east and west and advised him to write a book about the underlying harmony between Christian and Hindu scriptures.
Later Priya Nath Karar was formally initiated into Swami order and took the monastic name of Sri Yukteswar. His name is suffixed with Giri as he belonged to the Giri ("mountain") branch of the Swami Order.
Swami Sri Yukteswar wrote the book as advised by Babaji to show the unity between world religions and it is now famous as 'The Holy Science'. In this book he explains the path to self realization comparing verses from Hindu and Christian scriptures.
In later years, Swami Sri Yukteswar sends his foremost disciple Paramahansa Yogananda to America to carry out the mission of spreading the liberating science of Kriya Yoga and to make the higher truths available to all throughout the world.
Sri Yukteswar entered mahasamadhi (a yogi's final conscious exit from the body) on March 9, 1936, at the age of 81, in Puri.
Later after his death, Swami Sri Yukteswar appears to Paramahansa Yogananda in physical body and explains to him various facts about astral worlds. This demonstration of the amazing resurrection of Swami Sri Yukteswar was described by Yogananda in the 'Autobiography of a Yogi' in detail. In this context, Yogananda quotes Sri Yukteswar 'Grieve not for me; rather broadcast everywhere the story of my resurrection...New hope will be infused into the hearts of misery-mad, death-fearing dreamers of the world."
Describing about the self realized master Swami Sri Yukteswar, Yogananda applies this saying from Hindu scriptures: 'In shallow men, the fish of little thoughts cause much commotion. In oceanic minds, the whales of inspiration make hardly a ruffle."