Require multiple files

I am building a PHP application that uses a select menu to build email templates. The templates are broken into reusable parts (each is a separate html file). Is there an easy way to require multiple files with one expression? (my PHP is really rusty...)

Essentially I want to do something like:

function require_multi() {
    require_once($File1);
    require_once($File2);
    require_once($File3);
    require_once($File4);
}