Sir Peter, founder of the Royal Shakespeare Company and director of the National Theatre, died aged 86, in September. Check out a full list of winners here!
The Olivier Awards are Britain's most prestigious stage prizes.
Film actor Sir Roger Moore, US pop star David Cassidy and RSC co-founder John Barton were among those whose names and faces were projected on a screen.
They may as well be called the "Hamilton" awards this year.
WWE Unveils the Full WrestleMania 34 Set
Rocket League has been a partner for many recent WWE events, and continues that sponsorship heading into WrestleMania 34. Two of the biggest names in the match, Rawley and Corbin, have already won it, so I don't think we'll see that again.
In a statement on Monday, SOLT described Sir Peter as "a wonderful and inspiring figure within the United Kingdom theatre industry" who was "sorely missed".
SOLT described Sir Peter as a "peerless British director and theatre impresario" after his death.
The society added that it had arranged for theatre lights in London's West End to be dimmed when he passed away a year ago.
With seven wins altogether including Best Actor In A Supporting Role In A Musical (Michael Jibson), Best Lead Actor (Giles Terera), Theatre Choreographer, Lighting Design, Sound design and, of course, Best New Musical, not to mention writer Lin-Manuel Miranda's Outstanding Achievement In Music, it was a landslide win for the American history bonanza.
The drama which is set in rural Derry in 1981 against the backdrop of the Troubles, won the best play and best director for Sam Mendes, while Laura Donnelly was named best actress. Best new comedy went to James Graham for his play "Labour Of Love"; his other play "Ink" yielded a best supporting actor victory for Bertie Carvel.