If you don’t want to attach the default post category taxonomy, you can always create a new one specifically for pages. Insert this into your functions.php
file:
add_action( 'init', 'create_page_taxonomies' );
function create_page_taxonomies() {
register_taxonomy('page_category', 'page', array(
'hierarchical' => true,
'labels' => array(
'name' => _x( 'Page Category', 'taxonomy general name' ),
'singular_name' => _x( 'page-category', 'taxonomy singular name' ),
'search_items' => __( 'Search Page Categories' ),
'all_items' => __( 'All Page Categories' ),
'parent_item' => __( 'Parent Page Category' ),
'parent_item_colon' => __( 'Parent Page Category:' ),
'edit_item' => __( 'Edit Page Category' ),
'update_item' => __( 'Update Page Category' ),
'add_new_item' => __( 'Add New Page Category' ),
'new_item_name' => __( 'New Page Category Name' ),
'menu_name' => __( 'Page Categories' )
),
'public' => true,
'rewrite' => array(
'slug' => 'page-category',
'with_front' => false,
'hierarchical' => true
)
));
}
This is a fairly bare-bones new taxonomy, and there are plenty of other options available, of which there is a complete listing in the WP Codex.
UPDATE:
I believe that this is what the whole loop would look like:
<?php
wp_reset_query();
$query = new WP_Query(
array(
'post_type' => 'page',
'tax_query' => array(
array(
'taxonomy' => 'page_category',
'field' => 'term_id',
'terms' => 541
)
)
)
);
if ( $query->have_posts() ) :
while ( $query->have_posts() ) : $query->the_post(); ?>
<div>
<?php
if ( has_post_thumbnail() ) :
the_post_thumbnail( array(150,150) );
else : ?>
<img class="alignleft" src="https://wordpress.stackexchange.com/questions/253133/<?php echo get_bloginfo("template_url"); ?>/images/empty_150_150_thumb.gif" width="150" height="150" />
<?php
endif; ?>
<div class="entry">
<h3 class="blog_header"><a href="<?php echo get_permalink(); ?>" rel="bookmark" title="Permanent Link: <?php the_title(); ?>"><?php the_title(); ?></a></h3>
<?php the_excerpt(); ?>
<a class="button_link" href="<?php the_permalink(); ?>"><span>Read More</span></a>
</div>
</div>
<?php
endwhile;
endif; ?>