Holly Marie Combs is remembering her "Charmed" co-star Shannen Doherty.
On Monday, Combs shared a moving tribute to Doherty on Instagram, who died at the age of 53 on Saturday, July 13, after a yearslong battle with cancer, a representative said.
"My better half of 31 years," Combs began in the caption of her Instagram post, which featured a series of photos of the both of them from over the years. "There is a hollow in my chest and I can't seem to catch my breath. A part of me is missing even though I know exactly what you would say to me right now. I know exactly what you would tell me to do right now."
"I know your undying spirit will live in me and my kids who you loved as your own," she continued. "They will walk with your sense of purpose and pride. They will be truthful and stand up for what is right."
"Your fire will live on in them and the many other Charmed ones you helped raise. A fierce fighter til the end," Combs said. "My most ardent champion. My loyal protector. My best friend. You taught me the meaning of family. You were and will be forevermore my sister. I love you."
Doherty played Prue Halliwell on "Charmed," and Combs portrayed Piper Halliwell, Prue's sister. The show followed a group of witches who used their powers to fight evil.
Rose McGowan, who replaced Doherty as the third star of "Charmed," said Doherty had the "heart of a lion."
"Passion for craft is often mislabeled as trouble. Shannen was passion. I met her in the 90s and was awed. Getting to really know her later in life, a beautiful gift. This woman fought to live," McGowan said in an Instagram caption that was accompanied by pictures of Doherty as a child and an adult.
"Shannen knew how to be a star because she was one since childhood. Her work ethic inspiring to the end," McGowan added.
McGowan honored Doherty as a "force of energy" that would live forever.
"Rest now warrior," she said.
Doherty's "Charmed" co-star Brian Krause, who portrayed Leo Wyatt on the show, also shared a post about Doherty and said he's "truly heartbroken" by her death.
"You showed me what strength is," Krause said. "You taught me to be fearless and live with purpose. To know your value and stick to your determinations. Forever loved!"
More from the Hollywood community, which Doherty had been a part of since she was a child when she played Jenny Wilder in "Little House on the Prairie," also reacted with sadness and shock. Her "Beverly Hills, 90210" costars shared moving tributes to Doherty, who played Brenda Walsh on the series.
"Our connection was real and honest," Jennie Garth wrote, in part, on social media, alongside photos of herself with Doherty. "We were so often pitted against each other but none of that reflected the truth of our real relationship which was one built on mutual respect and admiration."
The actress, who played Kelly Taylor in the series, continued, "She was courageous, passionate, determined and very loving and generous. I will miss her and will always honor her deeply in my heart and in my memories. My heart breaks for her family and Bowie and all the people who loved her."
Tori Spelling, who played Donna Martin on "90210," shared a photo of herself with Doherty on her Instagram Stories, along with several broken heart emojis.
"I don't have outward words yet, but WE knew and that's what matters," she wrote on the photo.
Jason Priestly, who played Brandon Walsh, the twin of Doherty's Brenda, expressed his condolences.
"Shocked and saddened to hear about the passing of my friend Shannen. She was a force of nature and I will miss her. Sending love and light to her family in this dark time," Priestly said on Instagram.
Carol Potter, who played the matriarch of the Walsh family, said she, too, was shocked and saddened.
"What a journey she has been on! Gone too soon. Throughout, she stayed true to herself and gave us an example of courage and perseverance in facing her own death. May she rest in peace," she said on Instagram.
James Eckhouse, who portrayed the patriarch of the Walsh family, Jim, said her death was a "loss."
"She was ferocious in her work, ferocious in her love, ferocious in her long courageous battle with cancer. Shannen, we will miss you dearly," he wrote on Instagram.
Gabrielle Carteris, who starred as Andrea Zuckerman in the beloved teen drama, also shared her condolences. She invoked the memory of actor Luke Perry, who starred as Dylan McKay, and who died in March 2019 of a massive stroke. He was 52.
"So young - so sad. May you RIP Shannon [sic]. I know Luke is there with open arms to love you," she wrote on Instagram.
Brian Austin Green, who played David in the series, mourned Doherty as a sister.
"Shan. My sister. You loved me through everything. You were a big part of my understanding of love. I'll miss you more than I know how to process right now. Thank you for the gift of you," Green wrote on his Instagram story.
MORE: Shannen Doherty, 'Beverly Hills, 90210' and 'Charmed' actress, dies at 53Actress Olivia Munn, who has been open about her battle with cancer, said the late actress faced her diagnosis "with such dignity, strength and grace."
Director Kevin Smith credited Doherty for changing the dynamic of '90s culture.
"Long before any other pop culture figure "broke the internet" @theshando singlehandedly shattered it in the early 90's. This is an incredible accomplishment considering the internet as we know it didn't even exist yet," he wrote, alongside a carousel of pictures of him and the actress.
Doherty, who starred in Smith's 1995 "Mallrats," "was a true talent, and she became a good friend," Smith said.
Smith, who said Doherty was "no shrinking violet," added that he was thankful for their 30 years of friendship.
"She's died way too soon. I already miss you, Do-Do. Thank you for going to the Mall with me - and for thirty years of friendship. My Canadian pal was right: you are (and always will be) an American icon," he said.
Dave Coulier remembered Doherty as having "a beautiful smile. Today, I'll also think about the women in my life who all succumbed to cancer - my mom, my sister, Sharon and my niece, Shannon, who all were so strong and so beautiful."
Sarah Michelle Gellar also took to Instagram to pay tribute to her friend and asked her followers to "honor her" by donating to animal charities because Doherty loved animals.
"How do you possibly find the right words to sum up 30 years of friendship? I keep reminding myself it only hurts this much because, there was so much love," Gellar wrote in the caption of her post. "Thank you, for all your kind words and support. I love all the messages about how @theshando was important to you. So let’s honor her."
"I know that would make our girl happy (and illicit that deep throaty laugh we all loved) 💔 💔💔," she added.