Music mogul Russell Simmons was reportedly the first to confirm news of the birth, tweeting, "Congrats to my good friend Beyoncé and Jay-Z."
Hov's protégé Rihanna and Bad Boy boss Diddy were also among the celebrities who rushed to tweet their congratulations.
While the Carters have not yet released an official statement on the birth, many of their friends and colleagues have confirmed the unusual name choice. Initial reports had the new princess named Ivy Blue, but close friends of the superstar couple later confirmed it was the other way around.
"Welcome to the world, Blue," Beyoncé and Jay-Z's good friend, Gwyneth Paltrow, tweeted yesterday. "We love you already."
When asked by one of her Twitter followers whether the baby's name was "Ivy Blue or Blue Ivy" Gwyneth replied, "It's Blue Ivy!"
Blue Ivy, eh? We haven't heard a baby name drum up this much controversy since Nick and Mariah introduced Monroe and Moroccan to the world!
Although it sounds random, the name is anything but. Jay-Z released three albums dubbed The Blueprint in 2001, 2007 and 2009. "Blue" also has four letters and "Ivy" is inspired by the roman numerals IV: Mama Bey's favorite number.
And of course, there's the dish that Jay actually named his first born after one of his ex-girlfriends.
It's never been confirmed, but the "Big Pimpin'" hit-maker was briefly, romantically linked to Grammy-nominated R&B songbird Blu Cantrell back in the early 2000s. Cantrell is best remembered for her 2001 pop smash "Hit 'Em Up Style (Oops!)." The mega-hit was followed by the moderately-successful "Breathe," which featured reggae impresario Sean Paul.
Blu eventually dropped off the pop radar after it was discovered that she had accepted $500 to pose nude in a spread for Black Tail magazine (Think Playboy with a hint more color…) when she was in her early twenties. Despite Cantrell's -- ahem -- questionable morals, Jay-Z was reportedly quite smitten with the biracial beauty. He was left in tears when she put the kibosh on their relationship in early 2002.
Jay-Z and Beyoncé met, and began dating, later that year. The rest, as they say, is history.
Born at New York's Lenox Hill Hospital, baby Blue was reportedly delivered by a scheduled Caesarean section. The 30-year-old first time mom gave birth in a private wing with husband Jay-Z by her side.
The couple paid a whopping $1.3 million to book out the entire fourth floor of the Manhattan medical center, according to reports. Beyoncé checked in on Friday night under the pseudonym "Ingrid Jackson." On Saturday night, delivery men were spotted bringing bags of takeout and bottles of red wine to the heavily-guarded hospital wing.
By 11 p.m., all hospital staff were barred from the fourth floor and one doctor was left complaining that he was unable to check up on his patients. As part of the heavy security surrounding the birth, packing tape was placed over the lenses of hospital CCTV cameras and staff were made to turn in their phones before entering the building.
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