Simpson celebrates son's first birthday

Ashlee Simpson's son celebrated his first birthday on Friday.

The former Melrose Place actress wrote on Twitter that the time leading up to her son Bronx's first birthday has been the "greatest year" of her life, reports Us Weekly.

The 25-year-old wrote: "BX's 1st bday tomorrow! My angel is going to be a year! The greatest year of my life."

Simpson's husband Pete Wentz also posted a message for his son and thanked his friends for recording lullabies.

Wentz wrote: "Happy birthday bx. you don't have twitter and cant read this. Thanks to all my friends that recorded lullabies. Can't believe it's been a year."