Johnny and June. You don't even need to say their last names; the love story of Johnny Cash and his wife June Carter Cash is one of the most iconic of all time.

Cash and Carter met in 1956 at the Grand Ole Opry; Carter was singing background vocals for Elvis Presley at the time ... and Cash was married to another woman, Vivian Liberto. But a little over a decade later, in 1967, and Cash and Liberto finalized their divorce, and on Feb. 22, 1968, the "Man in Black" proposed to Carter in London, Ontario, Canada.

Cash and Carter Cash got married on March 1, 1968; in 1970, their one child together, John Carter Cash, was born. As with every real-life story, theirs wasn't perfect: It was tumultuous and often wrought with tension over addictions, betrayal and other hard issues. But the love the couple shared continues to shine on through the ages.

In a romantic love letter to Carter Cash on her 65th birthday, Cash wrote, "You still fascinate and inspire me. You influence me for the better. You're the object of my desire, the No. 1 Earthly reason for my existence." He went on to say, "We got old and got used to each other. We think alike. We read each others [sic] minds. We know what the other wants without asking. Sometimes we irritate each other a little bit. Maybe sometimes we take each other for granted. But once in a while, like today, I meditate on it and realize how lucky I am to share my life with the greatest woman I ever met."

The feeling was mutual: "The love that John and I share with our love for Christ is one of the most precious gifts God could have given us," Carter Cash said of her husband.

Throughout their 35 years of marriage, Cash and Carter Cash shared the stage and released several collaborative albums, including Carryin' on With Johnny Cash and June Carter, Johnny & June and June Carter and Johnny Cash: Duets. In 2003, the two passed away within four months of one another.

As you click through the photo gallery above, you'll see the couple connecting onstage and off. The joy that beams from their faces is impossible to miss.