When I started working as a web developer, PHP was the first language I learned that was 100% web oriented.
Back then I believe it was PHP3 or something like that. At the time, PHP was pretty new to the web, PERL was the main denominator.
PHP today is hated and loved, and I’m not going into that path here, I’m very programming language agnostic. My mantra is “use what’s best for the job”. However, back then PHP was getting lot of traction, mostly because it was very easy to work with and to setup/deploy. Nothing, even today, beats the LAMP stack.