The arrival of baby Luna marks a new chapter for one of rock music's most famous families and officially makes Keith a great-grandfather for the first time.
Luna is the first child for model Ella and her long-term boyfriend Sascha von Bismarck, 31, a photographer from one of Europe's most distinguished aristocratic families.
The couple's happy announcement was met with an outpouring of love from friends and family, including several well-known names from society and fashion circles.
Burberry campaign star Ella confirmed her pregnancy back in March with a black-and-white photograph showing her growing baby bump.
Her latest post confirming the birth, was flooded with congratulations from her famous friends.
Princess Olympia of Greece wrote, "The most beautiful."
Socialite Daphne Guinness chimed in, "Happy Birthday! So so sweet."
Ella is the daughter of Marlon Richards, Keith's eldest son from his long relationship with the late model and actor Anita Pallenberg, who died in 2017 aged 75.
