Michael Jackson's sister Rebbie Jackson is mourning the passing of her husband, Nathaniel Brown.

After fighting a long battle with cancer, Brown died on Sunday, Jan. 6. He leaves behind not only his wife, but three children -- Stacee Brown, 40, Yashi Brown, 35, and their son Austin Brown, 27, who is a singer/songwriter.

Rebbie and Nathaniel were high school sweethearts, the two wedded in 1968, and enjoyed 44 years of marriage together. Jackson has yet to comment on her husband's death but her son has been celebrating his father's legacy via Twitter.

The King of Pop's nephew wrote "I love you Dad.. Thank you for showing me unconditional love and the example of being a good person ... Thank you all for the amazing love you have been giving me and my family."

In another post, the 27-year-old uploaded his parent's wedding photo and honored their commitment to one another. "44 years of marriage and inseparable till the end. Love u Dad," he wrote.