The biopic is a well-trodden path in Hollywood, and often Oscar-bait too (which explains why they keep making them).
In production at the moment are a biopic of Freddie Mercury, starring Mr. Robot's Rami Malek – who is looking sensational as the Queen frontman – and Joaquin Phoenix (no stranger to the genre, having played Johnny Cash in Walk the Line) will be seen next year in Mary Magdalene as popular figure from the past, Mr Jesus Christ.
But casting is key.
Screw up the lead and you've got a whole lotta problems on your hands yet, as you will see below, there are times when fortune favours the brave. On occasion, the left-field choice can pay huge dividends.
Here are eleven times when biopics picked some really strange actors to star in their biopics.
1. Robert Pattinson as Salvador Dalí
Yup, you're reading correctly. This is a surrealist dip into movie casting in two ways – the one-time Harry Potter actor played Dalí in the 2008 film Little Ashes.
The same year as he debuted as Edward Cullen in the Twilight saga, Pattinson portrayed the eccentric Spanish artist as a teenager. Although the film didn't exactly get people talking (or even watching), Pattinson managed to get through unscathed.
Just recently, Sky announced that Poirot star David Suchet will play Dali in the new series of Urban Myths.
2. Lindsay Lohan as Elizabeth Taylor
Predictably, when Lohan was lined up to play the troubled actress, the internet got unhappy. But who better to play the double-Oscar winner than a like-minded soul with a similarly problematic life?
As it transpired, everyone was right.
The Mean Girls star's performance was considered utterly atrocious in 2012's Liz & Dick, falling in to the "so bad it's good" category.
3. Leonardo DiCaprio as J Edgar Hoover
Not so much as bad casting as just plain odd.
Clint Eastwood cast the Titanic heartthrob in 2011's J Edgar, a biopic of the FBI boss famed neither for his Hollywood looks nor likability. Bit of a stretch, even for DiCaprio.
The film failed to get anyone excited, though Leo's portrayal was universally praised.
4. Ashton Kutcher as Steve Jobs
When the Dude, Where's My Car? star was announced to play the Apple founder in Jobs, people were a little sceptical.
Not surprising given he'd just started on sitcom Two and a Half Men and was hardly known for dramatic roles.
The actor himself admitted the negativity spurred him on to do good – as a tech junkie he was passionate about the subject, and physically he was a good fit. Sadly, the 2013 film wasn't well-received and earned Kutcher a Razzie nominee for Worst Actor.
5. Colin Farrell as Alexander the Great
Alexander the Great was tutored by revered philosopher Aristotle in his youth and became one of history's greatest military tacticians. He was a king of multiple domains and an Egyptian Pharoah. There are a plethora of cities named after this legend. And he was Macedonian.
Colin Farrell played Bullseye in Daredevil. And he's Irish.
The miscasting, however, of Farrell in 2004's Alexander was the least of the film's problematic issues, with historians, critics and audiences equally displeased with the movie.
(We should add that Colin has gone on to do some amazing work since then, such as In Bruges and The Lobster – just in case you thought we were being mean.)
6. Cate Blanchett as Bob Dylan
Now this is the very definition of weird casting.
Weird, but brilliant.
2007's I'm Not There was a fascinating take on the folk singer from Todd Haynes, featuring Blanchett along with Christian Bale, Marcus Carl Franklin, Richard Gere, Heath Ledger, and Ben Whishaw all playing various facets of Bob Dylan over the course of his eclectic career.
It was bold casting and paid off, with Cate in particular singled out for her portrayal as mid-Sixties Bob. The actress was Oscar-nominated and won a Golden Globe – the only "Dylan" in the film to receive any award recognition.
7. Benedict Cumberbatch as Julian Assange
Few eyebrows were raised when TV's Sherlock was hired to the play Australian WikiLeaks founder Julian Assange in 2013's The Fifth Estate.
Talented actor, we thought, he can easily play a computer guy who likes to spoil secrets and avoid Sweden.
It wasn't until the first images from the movie's production emerged, showing Cumberbatch as Assange, when it occurred to us that he looked like some sort of strange white-haired sci-fi lion. And we still can't see past that.
8. Anne Hathaway as Jane Austen
Another entry that falls into the "they're too good-looking to play that person!" category.
Without being unkind to celebrated English author Jane Austen, the statuesque and very glam Devil Wears Prada star would not have been the first, or even one hundred and first, choice to play her lookalike. Yet she was the lead in 2007's Becoming Jane.
Oh, and she's also American.
However, Hathaway won praise and even a BIFA nomination, thus adding to her impressive and varied oeuvre.
9. Mick Jagger as Ned Kelly
Ned Kelly, for those not familiar with Australian history, was a bush-dwelling Irish-Aussie killer who was executed for his crimes at the tender age of 25.
Jagger, as we're sure you're aware, is the frontman of popular beat combo The Rolling Stones.
A tad on the posh side, British and, most importantly, not an actor, Dartford's Mick was not the perfect choice. Or even a good one. Everyone disowned Ned Kelly (1970), with even Jagger admitting he'd never seen it. We recommend you don't bother either.
10. Taron Egerton as Eddie "The Eagle" Edwards
Egerton fans were left in tears when the handsome young actor was transformed into some kind of Bo' Selecta character in last year's Eddie the Eagle.
Edwards' good looks were buried behind huge comedy specs and a classically-camp Eighties moustache – his hardy Kingsman reputation left many wondering just how he could pull off playing this real-life punchline.
Thankfully, Egerton proved doubters wrong with a brilliant and funny portrayal of the sportsman in a heartwarming movie that is well worth a watch.
11. Geoffrey Rush as Peter Sellers
Dramatic Aussie actor Rush, who'd bagged numerous accolades for his serious roles in Shine and Quills, was most definitely a left-field choice to portray the English comic genius in 2004's The Life and Death of Peter Sellers. Though come to think of it, those two named films were both biopics too.
Sacha Baron Cohen, Steve Coogan and Robin Williams were all considered and would have been more obvious choices than the Australian star.
But the brave decision was a winner. Rush collected an Emmy, a Golden Globe and countless other nominations for his electric and engrossing performance.
