Mahanidhi Dasa: 1959 was a momentous year for Srila Prabhupada. Srila Prabhupada relates the events leading to his entering the renounced order of life.
Srila Prabhupada: “I was sitting alone in Vrindavan, writing. My Godbrother insisted to me, ‘Bhaktivedanta Prabhu, you must do it. Without accepting the renounced order of life, nobody can become a preacher.’ So he insisted. He wanted me to become a preacher, so he forced me through this Godbrother, ‘You accept.’ So, unwillingly, I accepted.“
Reference: Prabhupada at Radha Damodara by Mahanidhi Dasa