From 2005 to 2007, Menzies portrayed Marcus Junius Brutus, Julius Caesar's friend and later co-assassin, in the HBO/BBC historical drama series Rome (2005–07). He next appeared as William Elliot in ITV's production of Jane Austen's classic Persuasion, and Derrick Sington in Channel 4's feature length drama The Relief of Belsen, which chronicled the British liberation of Bergen-Belsen Concentration Camp at the end of WWII. In 2008, Menzies starred in two stylistically different mini-series. The first was BBC's anthology mini-series Fairy Tales, in an episode entitled The Empress's New Clothes, where he portrayed Aidee. Second was the series finale of BBC's Bonekickers, which followed a team of British archaeologists as they investigated mysteries and conspiracy theories surrounding historical artifacts. The next year saw Menzies return to episodic television with roles in ITV's legal drama Kingdom, alongside Stephen Fry, a special episode of BBC's comedy Pulling, and several episodes of BBC One's spy drama Spooks.