Making his debut with Jordan Grand Prix, Ralf moved to Williams in 1999, securing his first win with the team in 2001 at the San Marino Grand Prix.
Having stuck with the Grove-based outfit for six seasons, the 49-year-old made his final team switch to Toyota before exiting the sport in 2007.
Having won six grands prix between 1997 and 2007, and Michael's fruitful career granting him legendary status, the Schumacher's are the most successful sibling pairing the sport has ever seen.
The six-time race winner shared a picture with the man believed to be his partner in a moving post on his Instagram page.
The couple could be seen with their arms around each other, the image on Ralf's personal Instagram page captioned: "The most beautiful thing in life is when you have the right partner by your side with whom you can share everything."
Schumacher's son, David, commented on the post, saying: "I am very happy that you have finally found someone with whom you really feel that you feel very comfortable and secure, no matter if [it is] a man or a woman.
"I am 100% behind you dad and wish you all the best and congratulations."