"It's a great honour to take on this responsibility," McCullum said. "The Knight Rider franchises in IPL and CPL have become iconic and have set the standard in franchise cricket. We have fantastic squads in both KKR and TKR and I, along with the support staff will be looking to build on the success both franchises have enjoyed."
Less than a week ago, it had been learnt that McCullum would take over as head coach at Trinbago but only as assistant coach with the IPL franchise, following his retirement from all forms of the game earlier in the month. That's changed since, with the top job at the Kolkata franchise going to the former New Zealand captain, too.
KKR's chief executive Venky Mysore described him as an ideal candidate to take over from Jacques Kallis, the Kolkata coach till last season. "Brendon has been an integral part of the Knight Riders family for a long time," Mysore said. "His leadership qualities, honesty, positive and aggressive style, combined with his natural ability to bring the best out of the teams he has been a part of makes him ideally suited to lead both KKR and TKR as a head coach."
McCullum, 37, was expected to play in the Euro T20 Slam from August 30 as an icon player for Glasgow Giants but instead announced his retirement as a freelance cricketer.
It's understood that the decision to skip the new tournament was because Trinbago wanted him to helm the team at the CPL this year itself, and the dates of the two competitions clashed; the CPL starts from September 5. In any case, the Euro T20 Slam has since been cancelled because of financial difficulties.
Indeed, in his message on Instagram at the time of announcing his retirement, McCullum had mentioned that "the next chapter, in both media and coaching, will challenge me further".
Kolkata recently announced that they were parting ways with Kallis, their head coach, and Simon Katich, the assistant coach who was also the head coach at Trinbago.
McCullum had retired from international cricket in 2016, after the Christchurch Test against Australia, but continued to turn out in franchise-cricket leagues around the world, with stints in the IPL with Chennai Super Kings and Royal Challengers Bangalore, as well as Brisbane Heat in the Big Bash, Lahore Qalandars in the PSL and Trinbago in the CPL.
His association with the Knight Riders goes way back, as Mysore noted. An early pathbreaker of sorts in T20 cricket, McCullum's best in the format was the unbeaten 158 he made for the Kolkata team against Royal Challengers in the inaugural IPL game, in 2008.
In December 2018, McCullum went unsold at the IPL auction. In February, he called time on his BBL career with Heat after a relatively strong season in which he made 302 runs in 13 innings. At the time, he had expressed his desire to continue playing T20 cricket worldwide.
Only two weeks ago in London, McCullum was signed by Glasgow for the inaugural edition of the Euro T20 Slam, where he was to team up with Dale Steyn, among others. However, the desire to "plough on regardless" didn't appeal to him anymore.
"I owe it to myself and the teams I represent to close that chapter rather than just plough on regardless of what I know to be true," he wrote. "In T20 cricket, I've enjoyed so many varied challenges, I can leave the game knowing I left no stone unturned."