"Real Housewives of Beverly Hills" star Kim Richards' ex-husband Monty Brinson has passed away. Brinson died on Sunday Jan. 24 after a long battle with lung cancer, according to Us Weekly. He was 58.

His former brother-in-law Rick Hilton, who is married to Richards' half-sister Kathy, announced the devastating news on Instagram on Sunday night. "We have lost Monty Brinson after a brave battle with cancer," he wrote. "His heart was a big as the moon and he was loved by all he Met. He will be sorely missed. I love You always!"

"Kim is devastated," a source told People. Brinson and Richards were married from 1985 to 1988 and welcomed their daughter Brooke, who is now 29, a year after they married. They remained close friends after their divorce, especially in recent years as the 51-year-old reality star has been helping take care of him while he battled cancer.

Just a few months ago, she posted a sweet message to Brinson on his birthday. "Monty...Happy BD. Star light, Star Bright. First star I see every night," she wrote. "Always know your in my heart. I love you so much. We have come so far, let's keep it going. I'm right by your side forever! I wish for you happiness, courage, peace, laughter, love, strength and every you've ever dreamed of!"

Brinson had also been posting to social media recently and keeping his followers updated on his condition. In the days leading up to his death, he shared a sense of optimism with one post of a sign that read, "If you don't believe you won't receive!"

"Even though I'm facing death eye to eye which instead of being scared or put, I'm embracing it as I go forward with this journey. I pray my journey helps others in what lays ahead of them through their struggles," he captioned the photo. "Then it's all worth the pain which y'all make easier on me each day...I got the strength to fight it for all of us and I'm damn well going to try to make your life uplifting if I can...Today is going to be another great day no matter the pain keep throwing it at me I can take it nor will I let it over come my life."