Marcia is the Latin feminine of Marcius. Marcia (1st c. BCE) was the Roman noblewoman, wife of Cato the Younger. In the famous (and historically debated) episode, Cato gave Marcia in marriage to his friend Hortensius — then, after Hortensius's death, took her back as wife.
Featured in Lucan's Pharsalia and Dante's Divine Comedy (Inferno IV, Limbo of the Virtuous).
Marcia reduces to three — the number of Roman matron.