While it's not known what Harry said in his speech, one can assume it was full of hilarious anecdotes from the pair's childhood.
PEOPLE reports the two met at Ludgrove Prep School and have been friends ever since.
Charlie even recently delivered a speech at Harry and Meghan's wedding during the evening reception at Frogmore House.
Several reports claim he made fun of Harry's role as dormitory monitor during their school days, even though he was the 'worst behaved kid of them all.'
'All I wanted was a cuddle from my mummy,' he said. 'Instead, Harry nicked my teddy bear and chucked it out onto the roof.'
It's also been reported that Charlie made several 'ginger' jokes at good friend Harry's expense.
Charlie's older brother Thomas van Straubenzee is also Prince William's close childhood friend, and is the godfather to Princess Charlotte.
While at the wedding, Meghan was called out by royal fans for having a slight wardrobe malfunction.
You can read all about it here.