"Lord Sri Caitanya Mahaprabhu had three Raghus among His associates--Vaidya Raghunatha (vide Adi-lila 11.22), Bhatta Raghunatha and Dasa Raghunatha. Dasa Raghunatha became celebrated as the Raghunatha of Svarupa."
Caitanya-caritamrta, Antya lila 6:203
"Srila Raghunatha dasa Gosvami, the forty-sixth branch of the tree, was one of the most dear servants of Lord Caitanya Mahaprabhu. He left all his material possessions to surrender completely unto the Lord and live at His lotus feet. When Raghunatha dasa Gosvami approached Sri Caitanya Mahaprabhu at Jagannatha Puri, the Lord entrusted him to the care of Svarupa Damodara, His secretary. Thus they both engaged in the confidential service of the Lord. He rendered confidential service to the Lord for sixteen years at Jagannatha Puri, and after the disappearance of both the Lord and Svarupa Damodara, he left Jagannatha Puri and went to Vrndavana. Srila Raghunatha dasa Gosvami intended to go to Vrndavana to see the lotus feet of Rupa and Sanatana and then give up his life by jumping from Govardhana Hill. Thus Srila Raghunatha dasa Gosvami came to Vrndavana, visited Srila Rupa Gosvami and Sanatana Gosvami and offered them his obeisances. These two brothers, however, did not allow him to die. They accepted him as their third brother and kept him in their company.
Because Raghunatha dasa Gosvami was an assistant to Svarupa Damodara, he knew much about the external and internal features of the pastimes of Lord Caitanya. Thus the two brothers Rupa and Sanatana always used to hear of this from him. Raghunatha dasa Gosvami gradually gave up all food and drink but a few drops of buttermilk. As a daily duty, he regularly offered one thousand obeisances to the Lord, chanted at least one hundred thousand holy names and offered obeisances to two thousand Vaisnavas. Day and night he rendered service within his mind to Radha-Krsna, and for three hours a day he discoursed about the character of Lord Caitanya Mahaprabhu. Sri Raghunatha dasa Gosvami took three baths daily in the Radha-kunda lake. As soon as he found a Vaisnava residing in Vrndavana, he would embrace him and give him all respect. He engaged himself in devotional service for more than twenty-two and a half hours a day, and for less than two hours he slept, although on some days that also was not possible. I am struck with wonder when I hear about the devotional service he executed."
Caitanya-caritamrta, Adi lila 10:91:103
"A summary of this chapter is given by Bhaktivinoda Thakura in his Amrta-pravaha-bhasya as follows. When Sri Caitanya Mahaprabhu went into transcendental fits of ecstatic love, Ramananda Raya and Svarupa Damodara Gosvami attended to Him and satisfied Him as He desired. Raghunatha dasa Gosvami had been attempting to come to the lotus feet of Sri Caitanya Mahaprabhu for a long time, and finally he left his home and met the Lord. When Sri Caitanya Mahaprabhu had gone to Santipura on His way to Vrndavana, Raghunatha dasa Gosvami had offered to dedicate his life at the Lord's lotus feet. In the meantime, however, a Mohammedan official became envious of Hiranya dasa, Raghunatha dasa Gosvami's uncle, and induced some big official court minister to have him arrested. Thus Hiranya dasa left his home, but by the intelligence of Raghunatha dasa the misunderstanding was mitigated. Then Raghunatha dasa went to Panihati, and, following the order of Nityananda Prabhu, he observed a festival (cida-dadhi-mahotsava) by distributing chipped rice mixed with yogurt. The day after the festival, Nityananda Prabhu gave Raghunatha dasa the blessing that he would very soon attain the shelter of Sri Caitanya Mahaprabhu. After this incident, Raghunatha dasa, with the help of his priest, whose name was Yadunandana Acarya, got out of his house by trickery and thus ran away. Not touching the general path, Raghunatha dasa Gosvami secretly went to Jagannatha Puri. After twelve days, he arrived in Jagannatha Puri at the lotus feet of Sri Caitanya Mahaprabhu.
Sri Caitanya Mahaprabhu entrusted Raghunatha dasa Gosvami to Svarupa Damodara Gosvami. Therefore another name for Raghunatha dasa Gosvami is Svarupera Raghu, or the Raghunatha of Svarupa Damodara. For five days Raghunatha dasa Gosvami took prasada at the temple, but later he would stand at the Simha-dvara gate and eat only whatever he could gather by alms. Later he lived by taking alms from various chatras, or food distributing centers. When Raghunatha's father received news of this, he sent some men and money, but Raghunatha dasa Gosvami refused to accept the money. Understanding that Raghunatha dasa Gosvami was living by begging from the chatras, Sri Caitanya Mahaprabhu presented him with His own gunja-mala and a stone from Govardhana Hill. Thereafter, Raghunatha dasa Gosvami used to eat rejected food that he had collected and washed. This renounced life greatly pleased both Svarupa Damodara Gosvami and Sri Caitanya Mahaprabhu. One day Sri Caitanya Mahaprabhu took by force some of the same food, thus blessing Raghunatha dasa Gosvami for his renunciation."
Caitanya-caritamrta, Antya lila, Chapter 6 Introduction
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.