In honour of the Buffy star‘s 40th birthday on Friday, Doherty, 46, posted a heartfelt tribute in her friend’s honor on Instagram, in which she thanked her for her friendship and loyalty throughout the years.
“Happy Birthday @sarahmgellar I’m posting this pic because of the pure joy and fun, I am clearly having in your presence,” she wrote about the smiling throwback photo.
“From the moment we met, you embraced me, supported me and stood fiercely by my side. Never a moment of insecurity or feeling threatened between us. Instead, you only rooted for me and lifted me up,” she penned.
Doherty continued: “You are that woman that walks in a room and lights it up…. not only with your smile, but with your confidence, humility, intelligence and sense of ease. Naturally, you are an Aries!!! I love you. I’m proud of you. I also want you to come home now so we can celebrate!!! Happy birthday beautiful friend. You deserve the moon and more.”
“Shannen’s incredible,” Gellar recently told Entertainment Tonight about her close friend.
“What she’s done for other women going through it is so brave, and that’s what real bravery is — to be able to go through the hardest time of your life and show people it’s okay to be scared, and it’s okay to be vulnerable, and you can do it,” Gellar said.
In February, Doherty and Gellar attended an intense dance workout class together, which they documented heavily on social media. “The fact that she gets up and goes to those dance classes? The last thing I want to do is go to these really hard dance classes and sweat that hard and work that hard,” Gellar admitted. “But I have to remind myself that if she’s getting up there and doing it, then it’s important that I do it, too.”
This story originally appeared on PEOPLE.com.