Beyonce and Jay-Z Welcomed Daughter

Beyonce and Jay-Z welcomed a daughter Saturday night in New York, the little one's arrival coming via scheduled C-section, multiple sources confirm to E! News

And the pop 'n' hip-hop princess' name is Blue Ivy Carter

Friend and music mogul Russell Simmons was among the first to celebrate the arrival, tweeting the new parents: "congrats to my good friends Beyonce and Jay-Z."

Rihanna gave baby Blue a warm welcome, tweeting: "Welcome to the world princess Carter! Love Aunty Rih."

Beyonce and Jay-Z tied the knot in April 2008 after roughly six years of dating.