One of the most successful European groups of the decade, and one of the best-selling acts of all time with 380 million records sold, was the quartet ABBA. The most successful Swedish group of all time, ABBA first found fame when they won the 1974 Eurovision Song Contest. They became one of the most widely known European groups ever, as well as one of the few groups from a non-English speaking country to gain international success with several back-to-back No. 1 albums and singles in most of the major music markets. "Waterloo", "Mamma Mia", "Take a Chance on Me", "Knowing Me, Knowing You", "Dancing Queen", and "The Winner Takes It All" are just some of ABBA's most popular and most successful songs.