The songwriting partnership of Mick Jagger and Keith Richards, known as Jagger/Richards (and occasionally Richards/Jagger), is a musical collaboration whose output has produced the majority of the catalogue of The Rolling Stones. It is one of the most successful songwriting partnerships in history. Jagger and Richards adopted the nickname "The Glimmer Twins" after a vacation cruise they took to Brazil in December 1968/January 1969 with their then-girlfriends, Marianne Faithfull and Anita Pallenberg. An older English couple on the ship kept asking Richards and Jagger who they were. When they refused to reveal their identities, the woman reportedly kept asking, "just give us a glimmer" (as in "give us a hint about who you are"), which amused Jagger and Richards. In addition to Jagger and Richards's songwriting partnership, they have also produced or co-produced numerous Rolling Stones albums under the pseudonym The Glimmer Twins, after that experience together.