From The Spaghetti Western Database
The Dollar Trilogy (aka Dollars Trilogy)
Term referring to Sergio Leone's first three spaghetti westerns:
Please note that these films do not comprise a trilogy in the traditional sense. The stories have nothing to do with each other and they are not the same characters. But all three films feature Clint Eastwood as a nameless stranger, and other characters also playing similar archetypal figures. All three films are scored by Ennio Morricone and they came out subsequentially and were ultra successfull and influential on the entire genre.
See also: The Man with no Name