Livia Drusilla

Livia is the emperor Augustus's wife, and the most formidable mind in Rome. Sharp-tongued, immaculately composed, and never without a purpose, she manages her husband, her family, and the succession with the patience of someone playing a much longer game than anyone around her realises.

Siân Phillips plays her with icy, amused precision, delivering poisonous calculation in the same dry tone as small talk. The writing trusts her intelligence completely, letting her outthink every man in the Senate without raising her voice. She's chilling because she's never anything less than perfectly reasonable.