Optimal way to manage multiple HTMLs with the same code?

I am building my own photography website where dynamic content is the pictures.

Right now, I have seperate HTML files for each page, which is very inefficient when I make any code changes.

I tried javascript to handle the dynamic content, but back and forward navigation doesn't work. I am not sure if php is appropriate as it's server side scripting.

What would be an optimal way to update the dynamic content?