Aunt Agatha

Aunt Agatha is the ancient, formidable relic of the Poldark family, installed at Trenwith with her cats and her memories, guarding bloodline and propriety like a dragon guards gold. She is sharp-tongued, gossip-hungry, and openly scornful of anyone she considers beneath the family's standing — Ross's choice of wife very much included.

Caroline Blakiston plays her as pure, undiluted id — a woman who has outlived tact and sees no reason to acquire it now. The writing uses her as the family's living memory and its conscience of snobbery both, and she is at her best delivering a devastating line with the placid cruelty of someone who expects to be obeyed.