Mianning was the second son of Prince Yongyan, the 15th son and heir of the Qianlong Emperor. Even though he was Yongyan's second son, he was first in line after Prince Yongyan to his grandfather's throne. This was because according to the dishu system, his mother, Lady Hitara, was Yongyan's primary spouse whereas his elder brother was born to Yongyan's concubine. Mianning was favoured by his grandfather, the Qianlong Emperor. He frequently accompanied his grandfather on hunting trips. On one such trip, at the age of nine, Mianning successfully hunted a deer, which greatly amused the Qianlong Emperor. The emperor would abdicate five years after that incident, in 1796, when Mianning was 14. Mianning’s father Prince Yongyan was then enthroned as the Jiaqing Emperor, after which he made Lady Hitara (Mianning's mother) his empress consort. The elderly Qianlong would live three more years in retirement before dying in 1799, aged 88, when Mianning was 17.