Gwen Stefani's Kids Are All Grown Up — Get to Know Kingston, Zuma, and Apollo

Stefani's youngest son, Apollo, was born on Feb. 28, 2014. Apollo gets the middle name Flynn from his maternal grandmother's maiden name and Bowie from his paternal grandmother's maiden name.

On his ninth birthday, Stefani shared a selection of photos and videos featuring her and Apollo with Shelton. "My world is so much bigger with u in it, happy birthday, apollo ♥️♥️ i love u so much," she wrote on Instagram.