First they collabed on the #1 single 'Heartbreaker' and became friends. Around 2004ish LA Reid was looking for someone to replace him as President of Def Jam, he called Mimi for her thoughts on who should take up the position.
"hire Jigga!" Mariah told Reid, moments later JayZ entered the office. Reid joked that the pair choreographed this. “I was like wait, they choreographed this,” said Reid. “That was too good. He was so on time and it worked out.”
JayZ was president for 4 years, launching the career of now ritired popstar, Rihanna during his stay
Mods I checked both Jay and Mariah's tags, this hasn't been posted...i think