By the time He was twenty-four, Chaitanya Mahaprabhu had already transformed Nabadwip: a nightly gathering of devotees in a private courtyard had grown into open, town-wide sankirtana, the local Muslim administration had withdrawn its opposition, and even the town's most notorious sinners had been reclaimed. Yet Nimai — still, in the eyes of most of Bengal, a brilliant young householder pandit — became convinced that His mission of freely distributing love of Krishna to every soul, irrespective of caste or social station, could not fully succeed while He remained a grihastha (householder), because the honour and deference automatically extended to a married brahmana scholar in Bengali society would always stand between Him and the most fallen people He most wished to reach.
The renounced order of sannyasa carried exactly the opposite social signal: a sannyasi renounces all family ties, all claim to caste privilege, and depends on the charity of others for his very food, becoming in the eyes of society the equal of anyone, high or low. By formally accepting sannyasa, Nimai would strip away the last worldly distinction that stood between Himself and the people He had come to deliver — a decision consistent with, but far more drastic than, everything He had already been doing in the sankirtana movement.
Having resolved on this course, He is said to have left home quietly at night, travelling from Nabadwip to the town of Katwa on the banks of the Ganges, so as to spare His mother and young wife the anguish of watching Him depart. At Katwa He approached the sannyasi Keshava Bharati and requested initiation into the renounced order; despite Keshava Bharati's initial hesitation to accept as a disciple someone so evidently exalted, Nimai insisted, and Keshava Bharati performed the sannyasa ceremony, shaving Nimai's head, giving Him the danda (the sannyasi's staff) and kamandalu (water pot), dressing Him in the simple kaupina and bahirvasa of a renunciant, and bestowing on Him the sannyasa name by which He would be known for the rest of His life and for all the centuries since: Sri Krishna Chaitanya.
When word reached Nabadwip of what had happened, the devotees — led by Nityananda Prabhu and including Mukunda Datta and others — hurried to Katwa, arriving in time to witness the immediate aftermath. Sachi Devi and Vishnupriya, informed that Nimai had renounced the world without even a final farewell, were overcome with grief; the biographies do not soften this moment, describing at length the household's anguish at losing, in a single night, the son and husband on whom their whole domestic life had depended. Advaita Acharya and the assembled devotees eventually persuaded the newly sannyasi Krishna Chaitanya to travel first to Shantipura, to the home of Advaita Acharya, specifically so that Sachi Devi could see her son once more in His new condition before He departed for Puri — a meeting remembered as one of the most tender and sorrowful in the entire Vaishnava literature, mother and son both accepting, through tears, that His path now lay elsewhere.
From Katwa onward Sri Krishna Chaitanya belonged, in the fullest social sense, to no one household and no caste — a wandering mendicant sannyasi who would spend the following twenty-four years walking the length of India, teaching kings and outcastes with the same freedom, before finally settling at Jagannatha Puri for the last eighteen years of His manifest presence. Gaudiya Vaishnavas regard His acceptance of sannyasa not as a rejection of family life itself, which the tradition continues to honour, but as the deliberate, personal sacrifice through which the Lord removed every remaining social barrier between Himself and the most fallen souls of the world He had come to deliver.