JezK

get_header(); ?>

<?php if ( have_posts() ) : ?>

<header class="page-header">
					<h1 class="page-title">
					<?php
						/* translators: %s: Tag title. */
						printf( __( 'Tag Archives: %s', 'twentyeleven' ), '<span>' . single_tag_title( '', false ) . '</span>' );
					?>
					</h1>

<?php
						$tag_description = tag_description();
					if ( ! empty( $tag_description ) ) {
						/**
						 * Filters the default Twenty Eleven tag description.
						 *
						 * @since Twenty Eleven 1.0
						 *
						 * @param string The default tag description.
						 */
						echo apply_filters( 'tag_archive_meta', '<div class="tag-archive-meta">' . $tag_description . '</div>' );
					}
					?>
				</header>

<?php twentyeleven_content_nav( 'nav-above' ); ?>

<?php
				// Start the Loop.
				while ( have_posts() ) :
					the_post();
					?>

<?php
						/*
						 * Include the Post-Format-specific template for the content.
						 * If you want to overload this in a child theme then include a file
						 * called content-___.php (where ___ is the Post Format name) and that
						 * will be used instead.
						 */
						get_template_part( 'content', get_post_format() );
					?>

<?php endwhile; ?>

<?php twentyeleven_content_nav( 'nav-below' ); ?>

<?php else : ?>

<?php endif; ?>

</div>
		</section>

<?php get_sidebar(); ?>
<?php get_footer(); ?>

JezK

Edit File: tag.php