Short answers, pulled from the story.
The elder Vatsiputra established the Pudgalavada school in India during the third century BCE. This group emerged from the Sthavira Nikaya, a major branch of early Buddhism.
Pudgalavadins defined this entity as neither identical to nor different from the five aggregates. They asserted that while no permanent self exists, a person called pudgala does exist.
Emperor Harshavadana ruled between 606 and 647 CE. His sister Rajyasri joined the order as a nun, signaling high-level royal support for the sect.
Vibhajyavadins sharply criticized the sect's views as being too close to the concept of a self. Records of this debate appear in the Theravadan Kathavatthu attributed to Moggaliputtatissa around the third century BCE.
Valabhi University in Gujarat served as their primary center of learning until the eighth century. Inscriptions confirm communities existed in Mathura and Sarnath between the second and fourth centuries.
Only four of their original works survive today in Chinese translation. All surviving Pudgalavada texts are preserved only through these translations since the original Sanskrit canon has been lost to history.