The U.S. rockers played a set at the closing ceremony of the Invictus Games in London in September (14) after receiving a personal invitation from the British royal, who had organised the event.
Now Grohl has revealed he was left with no choice but to agree to join the bill after the prince sent him daily cell phone text messages begging him to play.
Grohl tells British Tv programme The One Show, "That all came about because Chris (Martin) from Coldplay texted me once and said, 'Hey, is it okay if I give Prince Harry your phone number?' and I said, 'Yeah, I guess' (and was thinking) 'What does he want?'
"So Prince Harry texted me and said, 'I want to talk to you about this show we are putting on,' so we talked on the phone about the Invictus Games and he said some of the lads really love the band and he would really love us to come and play at the Invictus Games...
"And he texted me almost every day to say, like, 'Are you gonna play?', 'Are you gonna play?', 'Are you gonna play?'. So I called my manager (and said), 'We've got to confirm the date, man!'... (Prince Harry) is the nicest guy in the world. He did such a good thing for those soldiers."
The Invictus Games involved more than 400 wounded servicemen and women from around the world competing against each other in nine disciplines including swimming, archery, and cycling. The closing ceremony at London's Queen Elizabeth Olympic Park also featured sets from Bryan Adams, Ellie Goulding, Kaiser Chiefs, and former soldier James Blunt.