Madonna revealed the three-year romance during a 2015 interview with Howard Stern.
Decades after Tupac Shakur and Madonna's relationship ended, new details are coming to light.
In a letter Tupac wrote to Madonna on Jan. 15, 1995 while serving time for sexual assault at Clinton Correctional Facility, the rapper explained why he called things off with the "Like a Virgin" singer. The letter will be auctioned off by Gotta Have Rock and Roll between July 19 and 28 with a starting bid of $100,000.
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"I've waited a long time 2 finally write this mainly because I was struggling to find all the answers that I wouldn't leave any unanswered questions. First and foremost, I must apologize to you because like you said I haven't been the kind of friends I know I am capable of being," Tupac wrote, later explaining that he broke up with Madonna because of her race.
"Can u understand that? For you to be seen with a black man wouldn't in any way jeopardize your career. If anything it would make you seem that much more open & exciting," he shared. "But for me at least in my previous perception I felt due to my 'image' I would be letting down half of the people who made me what I thought I was. I never meant to hurt you."
Tupac later referenced an interview where Madonna supposedly said, "I'm off to rehabilitate all the rappers & basketball players."
"Those words cut me deep seeing how I had never known you to be with any rappers besides myself. It was at this moment out of hurt & a natural instinct to strike back and defend my heart & ego that I said a lot of things," he said. "Can you feel me? In the time since, as u can see, I have grown both spiritually and mentally. It no longer matters how I'm perceived. Please understand my previous position as that of a young man with limited experience with an extremely famous sex symbol."
"I offer my friendship once again this time my stronger & focused. If you are still interested I would like to further discuss this with you but some of it couldn't wait. I felt compelled to tell you...just in case anything happened 2 me," he continued. "Please be careful Madonna. Everyone is not as honorable as they seem there are those whose hearts bleed with envy & evil. They would not hesitate to do you harm! Let my 5 bullets be proof of that!"
"I don't know how you feel about visiting me but if you could find it in your heart I would love to speak face to face with you," Tupac concluded the letter. "It's funny but this experience has taught me to not take time 4 granted."
Madonna revealed in a 2015 interview with Howard Stern that she had dated Tupac, who was fatally shot in 1996, for three years.
"One time I was mad at [David Letterman] when I said the f-word a lot, but the rest of the time was good," Madonna revealed. "I was in a weird mood that day. I was dating Tupac Shakur at the time, and he had got me all riled up about life in general. So, when I went on the show I was feeling very gangsta."
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The rapper's brother, Mopreme Shakur, confirmed the romance to Vlad TV later that year, revealing that he helped facilitate their relationship.
"She gave me a note to give to him; I was just happy she was giving him a note. Everybody was there. I went over and gave it to him. He was about the business and then they linked up. I would take him to her house and s**t when we got back to L.A.," he recalled. "They were a thing for a minute."
See more in the video below.