Led Zeppelin put out the album Led Zeppelin in 1969 .
Although the group was initially unpopular with critics , they achieved significant commercial success with albums such as Led Zeppelin 1970 , Led Zeppelin II 1969 , Led Zeppelin III 1970 , Led Zeppelin IV 1971 , Houses of the Holy 1973 , and Physical Graffiti 1975 .
Led Zeppelin