Steven Tyler has become a grandfather for the fourth time.

The Aerosmith frontman welcomed the newest addition to his family on Wednesday (10.05.17) after his second daughter, Mia, and husband Dan Halen became proud parents to their first child, a son called Axton.

Sharing their news on Instagram, the 38-year-old model wrote: ''The love of my life has finally arrived and I am now complete.

''No words can explain how I am feeling. Just pure unfiltered love.

''My son, Axton born on May 10th at 5.45 am (sic)''

There is also a picture of Steven holding the newborn, which the model captioned: ''Best day of my while entire life.

''I'm so grateful for my family and my lover for being here & being so supportive.

''And to the friends and family that came to welcome our new lil wolf cub Ax into the pack.(sic)''

The 69-year-old rocker is also grand parent to his actress daughter Liv Tyler's son Milo Langdon, 12 - whom she has with ex Royston Langdon - and two-year-old son Sailor and 10-month-old daughter Lula Rose Gardner, her children with husband David Gardner.

In March, the 'Crazy' hitmaker posted a picture onto his Instagram account to his 1.1million viewers showing Liv, 39, holding up her baby Lula with son Sailor next to him.

He captioned the image: ''If Mama ain't Gappy ... ain't nobody Gappy... @MissLivalittle's new #Mamasaid campaign makes everyone happy. (sic)''

Liv recently said she was ''forever changed'' when she had children and admits being a mother has made her more compassionate.

She said: ''The reality is far more exciting and beautiful than what you imagine. The moment you lay eyes on that little human you are forever changed. Being a parent yourself helps you to relate to all parents and your parents. It helps you to have more compassion for all parents everywhere.''