Get Category of Page that item is on.

Hi All,

I’m trying to make the category the title of the page. for example if a user clicks on a category and goes here:

http://www.mydomainname.com/category/camping

My page will show everything in that category with the title of “Camping”

However, my problem is that a lot of posts have multiple categories and my current code is getting the “first” category present, and not the main category that all the posts have in common

<h1 class="page_title">
<?php
$category = get_the_category();
echo $category[0]->cat_name;
?>
</h1>