Bob Geldof proposed to Jeanne Marine to ease his "suffocating" grief over daughter Peaches' death.
The 64-year-old musician was left devastated when his 25-year-old daughter passed away from a drugs overdose in April 2014 so brought forward his plan to pop the question to his long-term partner in order to "let some light" into his life.
He said: "We could either let time do its thing [to heal the grief], but time doesn't heal, it just accommodates.
"You just push it [grief] to the side until it forces its way to your foreconscious again, and then you have to move it and place it back to this deep dark dungeon.
"I thought, 'I have to do something'.
"I had already planned to ask her to marry me on her birthday. And then, because of Peaches, I thought it would be entirely inappropriate.
"And then we buried her - and the next day - I decided to let some air into the room.
"We were suffocating with grief - and we needed air in the room - and we needed light in that air.
"I'm getting Bono-ish here but love is all you need."
And the Boomtown Rats frontman admitted he and Peaches' sisters, Fifi, Pixie, and Tiger Lily, "couldn't have survived" the weeks following Peaches' passing if it weren't for Jeanne.
Recalling his proposal, he told Ray D'Arcy on RTE Radio One: "I asked a great friend of ours to host a dinner for her birthday. I got the ring, which resembled the planet Mars in its girth and size.
"I got up to thank her for the dinner and to say why we had this dinner given the week that was in it.
"I went on to say that I couldn't have survived this period - and the children couldn't have - without Jeanne.
"All of the women started blubbering and I dropped to one knee.
"She immediately grabbed the ring and I grabbed back and said: 'No, you have to answer me first before you get it'.
"[She said yes] and then we waited a year until she was 50 to do the dirty deed. On her 50th birthday we got married."