Robert Downey Jnr is blowing up box offices this month as billionaire philanthropist Tony Stark, aka Iron Man, in Avengers: Age of Ultron. A seasoned professional, Downey Jnr landed his first film role at the age of five in Pound (1970), playing – wait for it – a puppy. In 1992, his portrayal of Charlie Chaplin, in the Richard Attenborough-directed biopic of the British comic, received a royal stamp of approval when Queen Elizabeth attended its London premiere in Leicester Square and shook Downey Jnr’s hand. The American actor has portrayed other classic characters on screen, including Sherlock Holmes …

The London detective made his literary debut in 1887, in the novel A Study in Scarlet. The character is said to have been inspired by Joseph Bell, a surgeon at the Royal Infirmary of Edinburgh for whom Holmes’ creator had worked as a clerk. Like the fictional detective, Bell would draw broad conclusions from minute observations. The stories of Holmes and his sidekick, Dr John H. Watson, were created by Scottish author and physician Arthur Ignatius Conan Doyle …

Born on May 22, 1859, Conan Doyle was fascinated by mystical subjects, and was a friend of Harry Houdini, the Hungarian- American illusionist. At one point, Conan Doyle became convinced that Houdini possessed supernatural powers, while the magician insisted he only employed trickery to pull off feats such as walking through a brick wall. Houdini was apparently unable to convince the author of this, leading to a bitter fallout between the two. In 1902, Conan Doyle was made a Knight Bachelor by King Edward VII …

The second child of Queen Victoria, Edward was born on November 9, 1841. As the eldest son of the British sovereign, he became Duke of Cornwall and Duke of Rothesay. He also claimed the title Prince of Wales – Edward remains the longest-serving holder of that title, at 59 years (his great-great grandson, Prince Charles, has held the title for 56 years). There have been many film portrayals of Edward’s life, including the 2003 television drama The Lost Prince, in which he was played by actor Michael Gambon …

Irish-born Gambon is perhaps best known for taking over the role of Albus Dumbledore, in the Harry Potter film franchise, after actor Richard Harris died in 2002. Gambon left school aged 15 and was a qualified engineer by the time he was 21, with a passion for collecting antique guns, clocks and classic cars. In 1962, Shakespeare changed his life, when Gambon made his professional stage debut at the Gate Theatre in Dublin, as the “Second Gentleman” in Othello. He went on to star in a National Theatre production of Hamlet directed by Laurence Olivier and starring Peter O’Toole …

O’Toole was born in 1932 in either County Galway, in Ireland, or Leeds, in England – the actor claimed to have had birth certificates from each country. Of his childhood, O’Toole once joked, “I’m not working class … I come from the criminal class.” Perhaps the most criminal thing about O’Toole is the fact he had been nominated eight times for the Academy Award for best actor in a leading role without ever winning – a record. In 1962, he achieved international acclaim for playing T.E. Lawrence in the film Lawrence of Arabia. In 1997, one Hollywood star named the famed hell raiser as his favourite actor of all time, citing his “selfassurance in his sexuality”. That actor was fellow wild child Robert Downey Jnr.