Sri Sanatana Gosvami took his birth in 1488 A.D. (1410, Sakabda). As a child, he began his studies along with his brothers, from their maternal uncle's house in a small village called Sakurma near the capital of Gaura-desa. At the age of 27 he came to live at Braja, and remained there for 43 years. At the age of 70, Srila Sanatana disappeared on the full moon day of Asar in the year 1558 A.D.
In the conclusion of his commentary on the Bhagavata, the Laghu-Vaisnava-Toshani, Jiva Goswami describes the ancestral line of his uncle, Sanatana Goswami. This genealogy states that there was a king in Karnataka called Srisarvajana, who was known as Jagadguru due to his learning. Srisarvajana's descendant, Aniruddha, gave his kingdom equally to his two sons, Harihara and Rupesvara, but Harihara forcibly occupied Rupesvara's dominion and drove him away. Rupesvara then left Karnataka, taking shelter with King Sikharesvara of Paurastya. He later retired to Navahatta (Naihati near Kalna) in Bengal, where he associated with king Danujamardana. His grandson, Kumaradeva, moved to Bakla Candradvipa (East Pakistan). Rupa, Sanatana, and Anupama were among the many sons born in this brahmana family.
As the elder brother of Srila Rupa Gosvami, Sanatana was the topmost among the six Gosvamis of Vrndavana. Lord Caitanya Mahaprabhu instructed him at Varanasi, teaching him the detailed science of devotional service. Lord Caitanya sent Srila Sanatana Gosvami to Vrndavana and gave him a fourfold mission: to uncover the lost sites of Krsna's pastimes, to install deities of the Lord and arrange for Their worship, to write books on Krsna consciousness, and to teach the rules of devotional life. Srila Sanatana Gosvami, with the help of Srila Rupa Gosvami, fulfilled all parts of this mission.
Sri Sanatana Gosvami compiled many scriptures, including: Sri Brhad-bhagavatmrta, Sri Hari-bhakti-vilas and its Dig-darsani-tika, Sri Krsna-lilastava (dasam carit), Sri Bhagavata-tipani (Dasama-tippani) (commentary on Srimad Bhagavatam), Brihat-vaisnava-tosani (Laghu-tosani), and Dasama-carita.
Sanatana Goswami's trancendental position is glorified in Sri Kavi-Karnapura's Gaura-Ganodesha-Dipika (181):
"Rupa Manjari's closest friend, who is know by the names Rati-Manjari and Lavanga-Manjari, appeared in the pastimes of Shri Chaitanya Mahaprabhu as Shri Sanatana Goswami, who is considered to be a personal extension of the body of Shri Chaitanya Mahaprabhu."
"Sri Sanatana Gosvami is described in the Gaura-ganoddesa-dipika (181). He was formerly known as Rati-manjari or sometimes Lavanga-manjari. In the Bhakti-ratnakara it is stated that his spiritual master, Vidyavacaspati, sometimes stayed in the village of Ramakeli, and Sanatana Gosvami studied all the Vedic literature from him. He was so devoted to his spiritual master that this cannot be described. According to the Vedic system, if someone sees a Muslim he must perform rituals to atone for the meeting. Sanatana Gosvami always associated with Muslim kings. Not giving much attention to the Vedic injunctions, he used to visit the houses of Muslim kings, and thus he considered himself to have been converted into a Muslim. He was therefore always very humble and meek. When Sanatana Gosvami presented himself before Lord Caitanya Mahaprabhu, he admitted, "I am always in association with lower-class people, and my behavior is therefore very abominable." He actually belonged to a respectable brahmana family, but because he considered his behavior to be abominable, he did not try to place himself among the brahmanas but always remained among people of the lower castes. He wrote the Hari-bhakti-vilasa and Vaisnava-tosani, which is a commentary on the Tenth Canto of Srimad-Bhagavatam. In the year 1476 Sakabda (A.D. 1555) he completed the Brhad-vaisnava-tosani commentary on Srimad-Bhagavatam. In the year 1504 Sakabda (A.D. 1583) he finished the Laghu-tosani."
Caitanya-caritamrta, Adi lila 10:84
"In the First Wave of the book known as Bhakti-ratnakara, it is said that Sanatana Gosvami understood Srimad-Bhagavatam by thorough study and explained it in his commentary known as Vaisnava-tosani. All the knowledge that Sri Sanatana Gosvami and Rupa Gosvami directly acquired from Sri Caitanya Mahaprabhu was broadcast all over the world by their expert service. Sanatana Gosvami gave his Vaisnava-tosani commentary to Srila Jiva Gosvami for editing, and Srila Jiva Gosvami edited this under the name of Laghu-tosani. Whatever he immediately put down in writing was finished in the year 1476 Saka (A.D. 1555). Srila Jiva Gosvami completed Laghu-tosani in the year Sakabda 1504 (A.D. 1583)."
Caitanya-caritamrta, Madyam lila 1:35
"The Fourth Chapter of Antya-lila is summarized by Bhaktivinoda Thakura in his as follows. Srila Sanatana Gosvami came alone from Mathura to Jagannatha Puri to see Lord Caitanya. Because of bathing in bad water and not getting enough food every day while traveling on the path through Jharikhanda Forest, he developed a disease that made his body itch. Suffering greatly from this itching, he resolved that in the presence of Sri Caitanya Mahaprabhu he would throw himself under the wheel of Jagannatha's car and in this way commit suicide.
When Sanatana Gosvami came to Jagannatha Puri, he stayed under the care of Haridasa Thakura for some time, and Sri Caitanya Mahaprabhu was very happy to see him. The Lord informed Sanatana Gosvami about the death of his younger brother, Anupama, who had great faith in the lotus feet of Lord Ramacandra. One day Sri Caitanya Mahaprabhu said to Sanatana Gosvami, "Your decision to commit suicide is the result of the mode of ignorance. One cannot get love of God simply by committing suicide. You have already dedicated your life and body to My service; therefore your body does not belong to you, nor do you have any right to commit suicide. I have to execute many devotional services through your body. I want you to preach the cult of devotional service and go to Vrndavana to excavate the lost holy places." After having thus spoken, Sri Caitanya Mahaprabhu left, and Haridasa Thakura and Sanatana Gosvami had many talks about this subject.
One day Sanatana Gosvami was summoned by Sri Caitanya Mahaprabhu, who wanted him to come to Yamesvara-tota. Sanatana Gosvami reached the Lord through the path along the beach by the sea. When Sri Caitanya Mahaprabhu asked Sanatana Gosvami which way he had come, Sanatana replied, "Many servitors of Lord Jagannatha come and go on the path by the Simha-dvara gate of the Jagannatha temple. Therefore, I did not go by that path, but instead went by the beach." Sanatana Gosvami did not realize that there were burning blisters on his feet because of the heat of the sand. Sri Caitanya Mahaprabhu was pleased to hear about Sanatana Gosvami's great respect for the temple of Lord Sri Jagannatha.
Because his disease produced wet sores on his body, Sanatana Gosvami used to avoid embracing Sri Caitanya Mahaprabhu, but nevertheless the Lord would embrace him by force. This made Sanatana Gosvami very unhappy, and therefore he consulted Jagadananda Pandita about what he should do. Jagadananda advised him to return to Vrndavana after the cart festival of Jagannatha, but when Sri Caitanya Mahaprabhu heard about this instruction, He chastised Jagadananda Pandita and reminded him that Sanatana Gosvami was senior to him and also more learned, Sri Caitanya Mahaprabhu informed Sanatana Gosvami that because Sanatana was a pure devotee, the Lord was never inconvenienced by his bodily condition. Because the Lord was a sannyasi, He did not consider one body better than another. The Lord also informed him that He was maintaining Sanatana and the other devotees just like a father. Therefore the moisture oozing from Sanatana's itching skin did not affect the Lord at all. After speaking with Sanatana Gosvami in this way, the Lord again embraced him, and after this embrace, Sanatana Gosvami became free from the disease. The Lord ordered Sanatana Gosvami to stay with Him for that year, and the next year, after seeing the Ratha-yatra festival, he left Purusottama-ksetra and returned to Vrndavana.
After meeting Sri Caitanya Mahaprabhu, Sri Rupa Gosvami also returned to Bengal, where he remained for one year. Whatever money he owned, he distributed among his relatives, the brahmanas and the temples. In this way he completely retired and returned to Vrndavana to meet Sanatana Gosvami.
After narrating these incidents, Krsnadasa Kaviraja Gosvami has given a list of the main books of Sanatana Gosvami, Srila Rupa Gosvami and Jiva Gosvami."
Caitanya-caritamrta, Antya lila, Introduction
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.