Happy birthday, Peter Davison—you vulnerable, indecisive, Edwardian cricketer, you.Born Peter Malcolm Gordon Moffett, the English actor replaced long-running fan favorite Tom Baker as the Doctor in 1981.At age 29, Davison became the youngest actor to play the lead role—a record he retained for nearly three decades, until a boyish 26-year-old Matt Smith became the Eleventh Doctor in 2009.He was also the first to have seen the program as a kid; for Davison, the chance to portray the titular character was a chance to become his own childhood hero.“It is a most appallingly daunting part to take on, if only because Tom [Baker] had done it for seven years—and also because you can’t approach Doctor Who like any other part,” Davison told now-defunct sci-fi magazine Starlog in 1986.“In any other part that you’re playing in fiction, you can usually say, ‘Well, this character had this sort of background. He had parents like this, he went to this school,’” he continued. “But with the Doctor, he comes from Gallifrey. The man is 750 years old and has two hearts. You can’t draw many conclusions from that.”BBCDuring his three-year tenure as the renegade Time Lord, Davison and his revolving door of companions—Adric, Nyssa, Tegan Jovanka, Vislor Turlough, Kamelion, Peri Brown—encountered some of the Doctor’s most notorious foes, including the Daleks (“Resurrection of the Daleks”) and Cybermen (“Earthshock”).All while working concurrently on two other series, comedies Holding the Fort and Sink or Swim.But, on the advice of Second Doctor Patrick Troughton—who Davison watched on TV as a teenager—the actor quit the show after three seasons, in an effort to avoid being typecast.“Obviously, that was a factor when I said I wasn’t going to do a fourth year—the fact that I felt that period was about as long as I could do without becoming too fixed as the Doctor in people’s minds,” he told Starlog.He never actually left the Whoniverse, though. Davison returned to the franchise on numerous occasions, including 1993 multi-Doctor charity special Dimensions in Time, 1997 video game Destiny of the Doctors, and a series of Big Finish audio plays.He also appeared alongside Tenth Doctor David Tennant—his future son-in-law (and fellow April baby)—in “Time Crash,” a special episode written by Steven Moffat for Children in Need.And while he expressed interest in 2013’s “The Day of the Doctor,” Davison ultimately passed on the part. Instead, he wrote and directed Sixth and Seventh Doctors Colin Baker and Sylvester McCoy, respectively, in The Five(ish) Doctors Reboot—a spoof on the anniversary special.Cheers to 66, sir!Stream all of Doctor Who now for free with your Amazon Prime membership.