David and Victoria Beckham Send Sweet Birthday Messages to Son Brooklyn: 'We Are All So Proud'

'You can now officially take dad for a drink down the pub,' David wrote alongside a sweet throwback pic.

Happy birthday, Brooklyn Beckham!

David and Victoria Beckham's oldest son turned 18 on Saturday, and the famous couple couldn't help but celebrate with adorable photos on Instagram.

WATCH: Brooklyn Beckham Throws It Way Back in Adorable Pic With Dad David From His Parents' Wedding Day

David first shared a cute throwback snap of himself holding Brooklyn on the day he was born.

"So on this day 18 years ago this little man came into our lives.... To say we felt blessed is an understatement," he wrote. "From day one he never slept through the night the only way he would fall asleep is when I took him out in the car and it had to be BoyZone on the radio and he would drop right off.... Thank fully he now sleeps the whole night without needing a song."

"Brooklyn has gone from this beautiful baby boy to become this handsome , polite and driven young man .. I'm proud that he lived through my career with me and I'm even prouder about the person that he has become," he continued. "Happy birthday Bust you can now officially take dad for a drink down the pub X ❤ @brooklynbeckham@victoriabeckham."

WATCH: Victoria Beckham Shares Adorable Pic of David Beckham With Their Four Kids: ‘I Think They Love Him!’

Victoria, meanwhile, shared a sweet slideshow of her firstborn.

"I can't believe our baby is 18 today. We are all so proud and love u so much @brooklynbeckham x Happy Birthday Buster x Lots and lots of love x," she wrote before sharing another cute pic of Brooklyn as a kid.

WATCH: David Beckham and Son Brooklyn Rock Matching Rings

"I can't believe our baby boy is 18 today x The most beautiful,caring,talented young man.We are so proud and love you so much x xxxxx," she captioned the second post.

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Though Brooklyn Beckham is starting to make a name for himself, he recently revealed that he didn't know his parents were famous until he was 13 years old.

"I didn't actually know that they were big until I was about 13," he told Wonderland. "I went to a football game and people were shouting my dad's name and I was like, 'What?! Oh my God.' I don't look at them like that."

See more in the video below.