Not so long ago Colin Firth was on top of the world. At the very least he enjoyed a remarkable three-year hot streak between 2009 and 2011. His sad but dignified performance as a suicidal gay professor in Tom Ford‘s A Single Man (’09) resulted in critical huzzahs and award-season accolades. His stuttering King George VI in The King’s Speech (’10) led to several Best Actor prizes, including an Oscar. And his performance as the treacherous Bill Haydon in Tinker Tailor Soldier Spy (released in early ’12 but viewed at major festivals in late 2011) was seen as nearly equal to Gary Oldman‘s George Smiley and at least at par with Benedict Cumberbatch‘s Peter Guillam.

Colin Firth in the duddish, faint-pulse romantic drama Arthur Newman

But right after Firth won his King’s Speech Oscar in February 2011, his luck changed. Or perhaps he was infected with a slumber virus. Or he decided to snag a few paychecks while the getting was good. I only know that his last four films over the past three years — Gambit, Arthur Newman, The Railway Man and Devil’s Knot — have been critically panned as inept or lackluster sleepathons. Suddenly Firth became renowned for going into his “repressed British clod mode,” as Empire Kim Newman put it a couple of years ago, regardless of the role or the film. It now appears that Firth’s next film — a Rowan Joffe-directed thriller called Before I Go To Sleep, costarring Nicole Kidman and Mark Strong — is a B-level distraction, at best.

Firth might be poised for a comeback with his roles in two seemingly light-hearted films, Woody Allen‘s Magic in the Moonlight and Matthew Vaughn‘s The Secret Service, due later this year. And his performance as editor Max Perkins in Michael Grandage‘s The Genius (due sometime in ’15) might get his blood going again…who knows? There’s also a major part as an Oscar Wilde friend and confidante in Rupert Everett‘s The Happy Prince, but I don’t how real this project is.

Who was the last Oscar-winning actor to just plunge off a career cliff after their Academy triumph? Post-Monster’s Ball Halle Berry comes to mind. Who else?