It's Party Time! Kourtney Kardashian Receives Sweet Birthday Tributes From Travis Barker, Her Sisters & Mom

The celebratory Instagram posts are rolling in for Kourtney Kardashian, who turned 43 years old on April 18.

One of the first to mark the star's special day was Kim Kardashian, who shared a set of photos of the two of them wading in the waters wearing matching blue swimsuits.

"Each year around the sun with you I learn and grow and evolve more because of you!" gushed the mom-of-four. "Thank you for teaching me to always go for it and follow my heart even if no one else understands. They just aren’t on our growth path lol Happy Birthday @kourtneykardash! Happiness looks so good on you. I love you so much!!!"

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In the SKIMS founder's Instagram Story, she posted several adorable snaps from their childhood.

The birthday girl's mom, Kris Jenner, uploaded pictures of her eldest child throughout the years.

"Happy birthday to my beautiful daughter @kourtneykardash!!! You are my first born little angel and my very special best friend from the moment you were born. You are such an amazing daughter, mommy, sister, cousin, auntie and fiancé!!!!!!" she wrote in the caption. "I am so very proud of the woman you are and I thank God every single day for choosing me to be your Mommy…. I am so blessed and grateful to be on this journey of life with you and I love you more than I can ever explain… you are my heart ❤️ Happy Birthday sweet girl 🙏❤️🎂🎈."

Alongside a lengthy and emotional message, Khloé Kardashian shared unseen photos from a trip they took to Cabo in 2005.

"Happy birthday to one of the loves of my life! I’ve never seen you so happy. Your happiness is to the point that other people start foolishly smiling simply because they feel this incredible energy radiating off of you. It looks great on you boo. Bottle it up and never stop drinking your love potion," she captioned her post. "Every single year I love to profess my love to you. Every single year I make sure to remind you just how special you are to me. You are my best friend, my soulmate, my everything. Words don’t do our bond justice."

"If you know us than you know our relationship. You know how much I love and adore you. How much I look up to you. You know how happy I am to see you as you are today," continued the Strong Looks Better Naked author. "Kourt, I pray this birthday is one of your best ones yet. You have taught me that Life only gets better if you allow it to. You have taught me to live life to the fullest and to act as if no one is watching.In the wise words of the birthday girl 'my vibe right now is just living life'. Never stop baby girl! Found these epic pics from 2005 in Cabo. @kourtneykardash you’re welcome."

Kardashian's fiancé Travis Barker posted a black and white filtered photo of the two with the caption, "My best friend, my lover, my everything. Happy Birthday @kourtneykardash I love you ♾."