The band's eponymous debut album hit the charts in 1969 and is widely credited as a catalyst for the heavy metal genre. Plant stated that "During Led Zeppelin I, as far as I was concerned I thought that I was going to [leave the band] anyway....
Plant has commented that it is unfair for people to think of Zeppelin as heavy metal, as almost a third of their music was acoustic. I was quite nervous and didn't get into enjoying it until II." Released only a few months later was the band's second album, Led Zeppelin II, which many referred to as a piece-together album.
In July 1977, his son Karac died at the age of five while Plant was engaged on Led Zeppelin's concert tour of the United States. Plant retreated to his home in the Midlands and for months afterwards he questioned his future.
Karac's death later inspired him to write several songs in tribute: "All My Love" featured on Led Zeppelin's final studio album, 1979's In Through the Out Door, while "Blue Train" featured on Page and Plant's second and final (studio) album, 1998's Walking into Clarksdale.
This significantly affected the production of Led Zeppelin's seventh album Presence for a few months while he recovered, and forced the band to cancel the remaining tour dates for the year.
Page: When I auditioned him and heard him sing, I immediately thought there must be something wrong with him personality-wise or that he had to be impossible to work with, because I just could not understand why, after he told me he'd been singing for a few years already, he hadn't become a big name yet.
So I had him down to my place for a little while, just to sort of check him out, and we got along great. With a shared passion for music, Plant and Page immediately developed a strong relationship, and began their writing collaboration with reworkings of earlier blues songs.
This created legal trouble for the band over whether or not they plagiarized these songs.
During Led Zeppelin III, which was released in 1970, Page and Plant's relationship began to grow stronger.