After the death of Tipu, he continued to advice Lakshmi Devi, the queen regent to the newly installed monarch Krishnaraja Wodeyar III.

[citation needed] At the age of eleven, Purnaiah lost his father and had to seek employment to support his family.

This grocer had close contact with a rich merchant, Annadana Shetty, who supplied large quantities of groceries to Hyder Ali's palace and army.

Endowed with prodigious memory, proficiency in multiple languages, and sheer hard work, Purniah became the head of the accounting department, and minister, and a confidant and close advisor of the ruler.

Purniah thus played a key role in keeping the news of Ali's death confidential owing to adversaries who could have seized this advantage and tried to usurp power.

Soon, with lobbying efforts from Maharani Lakshmi Devi, Purniah met with George Harris, the commander-in-chief of the Madras Army, for the handing-over of the kingdom's government to the deposed Wadiyars.

A subsidiary alliance was struck, and the maharani became the Queen Regent of Mysore for the infant prince Krishnaraja Wodeyar III.

Under Maharaja Krishnaraja Wodeyar III, Purnaiah started releasing cash allowances to mathas, temples, and dargahs, which had stopped under the Company rule after Tippu's death.

In honour of Richard Wellesley, the Governor-General of Bengal, a stone bridge was constructed across the river Kaveri connecting Srirangapattana with Kirangur.

[9] A large number of public shelters open to locals and travellers were erected in the name of Krishnaraja Wodeyar III, which were known as "Dewan Purniah".

Methodical land surveys were conducted; borders were notified; and the posts of shekdars, amaldars, and tehsildars (tax officers) were created, positions that are still in force throughout modern South Asia.