Jeremy was born at Nampara in 1791. He had an elder sister, Julia Poldark, who died the year before he was born. Ross Poldark took some time to accept the idea of another child since he was grieving for his daughter and thought it was too soon.
In time, he accepted Jeremy. He had a close bond with his mother who he spent a lot of time with. She depended on Jeremy when his father became distant for a short time. He was often cared for by Jud and Prudie Paynter when his parents were away. In 1794, he accompanied his mother to the beach, where they looked into the ocean and wondered when Ross would be home from his search for Dwight Enys.
Jeremy was later joined by a younger sister, Clowance Poldark and attended her christening.