Shakespeare was Claudio Ranieri’s assistant in 2015-16 when Leicester created one of football’s greatest stories to win the Premier League.
He replaced Ranieri as manager in February 2017 but, having been appointed permanently later in June on a three-year contract, was sacked in October.
Shakespeare’s most recent role was another spell as Foxes assistant in April 2023 under Dean Smith, but he left after their relegation from the Premier League the following month.
During his playing career as a midfielder, he featured for Walsall, Sheffield Wednesday, West Brom, Grimsby, Scunthorpe, Telford and Hednesford.
Former Leicester boss Nigel Pearson, who worked with Shakespeare at five different clubs, said: “It’s difficult to put into words how I, and indeed everyone who came across or worked with Craig, will feel on hearing such devastating news.
“He is without hesitation one of the most wonderfully talented, emotionally understanding, calm, balanced and outrageously funny people I’ve had the privilege of calling my friend. Safe journey to the next destination my wonderful friend.
“You are loved and admired by us all, and every time we think of you, a smile, smirk, chuckle or memorable occasion will come to us. We truly are the lucky ones for having known ‘Shakey’.”