diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 9e0952ae21be62f42b41a0de3b4558bb28c70776..fceef401242bb49a4611bed8468db78be532d997 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,5 +1,6 @@
 Zen 7.x-5.x-dev, xxxx-xx-xx (development release)
 ---------------------------
+- #1347236: Convert page markup to HTML5
 - #1352308: Add HTML comments for region template suggestions
 - #1352296: Remove "with-navigation" class and make navigation bar display unconditionally
 - #1348032: Convert breadcrumb markup to HTML5
diff --git a/STARTERKIT/css/pages.css b/STARTERKIT/css/pages.css
index 17f81a003e302a4d53e5eaf53635ef561683a751..ae648057c2cbb2fcc85a42404e15cda24a444e63 100644
--- a/STARTERKIT/css/pages.css
+++ b/STARTERKIT/css/pages.css
@@ -80,6 +80,8 @@ body {
 }
 
 #site-slogan /* The slogan (or tagline) of a website */ {
+  margin: 0;
+  font-size: 1em;
 }
 
 .region-header /* Wrapper for any blocks placed in the header region */ {
diff --git a/STARTERKIT/sass/pages.scss b/STARTERKIT/sass/pages.scss
index 44b7df424da41dbda9a7446d0a8e1b4c7f09896d..4eda03ce2a201904e3aed19a59b7010a563edc1a 100644
--- a/STARTERKIT/sass/pages.scss
+++ b/STARTERKIT/sass/pages.scss
@@ -84,6 +84,8 @@ body {
 }
 
 #site-slogan { // The slogan (or tagline) of a website
+  margin: 0;
+  font-size: 1em;
 }
 
 .region-header { // Wrapper for any blocks placed in the header region
diff --git a/templates/maintenance-page.tpl.php b/templates/maintenance-page.tpl.php
index ef7a8a67b64c3aadff7dc3a18ae73b08107ee3d9..c67e070b0ed35c17142c2693f548d1a1e0933f0e 100644
--- a/templates/maintenance-page.tpl.php
+++ b/templates/maintenance-page.tpl.php
@@ -39,30 +39,30 @@
 
   <div id="page-wrapper"><div id="page">
 
-    <div id="header"><div class="section clearfix">
+    <header id="header"><div class="section clearfix">
 
       <?php if ($logo): ?>
         <a href="<?php print $base_path; ?>" title="<?php print t('Home'); ?>" rel="home" id="logo"><img src="<?php print $logo; ?>" alt="<?php print t('Home'); ?>" /></a>
       <?php endif; ?>
 
       <?php if ($site_name || $site_slogan): ?>
-        <div id="name-and-slogan">
+        <hgroup id="name-and-slogan">
           <?php if ($site_name): ?>
-            <div id="site-name"><strong>
+            <h1 id="site-name">
               <a href="<?php print $base_path; ?>" title="<?php print t('Home'); ?>" rel="home">
               <span><?php print $site_name; ?></span>
               </a>
-            </strong></div>
+            </h1>
           <?php endif; ?>
           <?php if ($site_slogan): ?>
-            <div id="site-slogan"><?php print $site_slogan; ?></div>
+            <h2 id="site-slogan"><?php print $site_slogan; ?></h2>
           <?php endif; ?>
-        </div><!-- /#name-and-slogan -->
+        </hgroup><!-- /#name-and-slogan -->
       <?php endif; ?>
 
       <?php print $header; ?>
 
-    </div></div><!-- /.section, /#header -->
+    </div></header><!-- /.section, /#header -->
 
     <div id="main-wrapper"><div id="main" class="clearfix">
 
@@ -83,9 +83,12 @@
         <?php print $navigation; ?>
       </div><!-- /#navigation -->
 
-      <?php print $sidebar_first; ?>
-
-      <?php print $sidebar_second; ?>
+      <?php if ($sidebar_first || $sidebar_second): ?>
+        <aside class="sidebars">
+          <?php print $sidebar_first; ?>
+          <?php print $sidebar_second; ?>
+        </aside><!-- /.sidebars -->
+      <?php endif; ?>
 
     </div></div><!-- /#main, /#main-wrapper -->
 
diff --git a/templates/page.tpl.php b/templates/page.tpl.php
index 9cc6a117d7d056ceae001ab222acc41b74ed3787..aff8794c6e64ec8105d4996018469c5ba529953f 100644
--- a/templates/page.tpl.php
+++ b/templates/page.tpl.php
@@ -72,48 +72,45 @@
 
 <div id="page-wrapper"><div id="page">
 
-  <div id="header"><div class="section clearfix">
+  <header id="header"><div class="section clearfix">
 
     <?php if ($logo): ?>
       <a href="<?php print $front_page; ?>" title="<?php print t('Home'); ?>" rel="home" id="logo"><img src="<?php print $logo; ?>" alt="<?php print t('Home'); ?>" /></a>
     <?php endif; ?>
 
     <?php if ($site_name || $site_slogan): ?>
-      <div id="name-and-slogan">
+      <hgroup id="name-and-slogan">
         <?php if ($site_name): ?>
-          <?php if ($title): ?>
-            <div id="site-name"><strong>
-              <a href="<?php print $front_page; ?>" title="<?php print t('Home'); ?>" rel="home"><span><?php print $site_name; ?></span></a>
-            </strong></div>
-          <?php else: /* Use h1 when the content title is empty */ ?>
-            <h1 id="site-name">
-              <a href="<?php print $front_page; ?>" title="<?php print t('Home'); ?>" rel="home"><span><?php print $site_name; ?></span></a>
-            </h1>
-          <?php endif; ?>
+          <h1 id="site-name">
+            <a href="<?php print $front_page; ?>" title="<?php print t('Home'); ?>" rel="home"><span><?php print $site_name; ?></span></a>
+          </h1>
         <?php endif; ?>
 
         <?php if ($site_slogan): ?>
-          <div id="site-slogan"><?php print $site_slogan; ?></div>
+          <h2 id="site-slogan"><?php print $site_slogan; ?></h2>
         <?php endif; ?>
-      </div><!-- /#name-and-slogan -->
+      </hgroup><!-- /#name-and-slogan -->
     <?php endif; ?>
 
-    <?php print theme('links__system_secondary_menu', array(
-      'links' => $secondary_menu,
-      'attributes' => array(
-        'id' => 'secondary-menu',
-        'class' => array('links', 'inline', 'clearfix'),
-      ),
-      'heading' => array(
-        'text' => $secondary_menu_heading,
-        'level' => 'h2',
-        'class' => array('element-invisible'),
-      ),
-    )); ?>
+    <?php if ($secondary_menu): ?>
+      <nav id="secondary-menu">
+        <?php print theme('links__system_secondary_menu', array(
+          'links' => $secondary_menu,
+          'attributes' => array(
+            'class' => array('links', 'inline', 'clearfix'),
+          ),
+          'heading' => array(
+            'text' => $secondary_menu_heading,
+            'level' => 'h2',
+            'class' => array('element-invisible'),
+          ),
+        )); ?>
+      </nav>
+    <?php endif; ?>
 
     <?php print render($page['header']); ?>
 
-  </div></div><!-- /.section, /#header -->
+  </div></header><!-- /.section, /#header -->
 
   <div id="main-wrapper"><div id="main" class="clearfix">
 
@@ -138,26 +135,39 @@
 
     <div id="navigation"><div class="section clearfix">
 
-      <?php print theme('links__system_main_menu', array(
-        'links' => $main_menu,
-        'attributes' => array(
-          'id' => 'main-menu',
-          'class' => array('links', 'inline', 'clearfix'),
-        ),
-        'heading' => array(
-          'text' => t('Main menu'),
-          'level' => 'h2',
-          'class' => array('element-invisible'),
-        ),
-      )); ?>
+      <?php if ($main_menu): ?>
+        <nav id="main-menu">
+          <?php print theme('links__system_main_menu', array(
+            'links' => $main_menu,
+            'attributes' => array(
+              'class' => array('links', 'inline', 'clearfix'),
+            ),
+            'heading' => array(
+              'text' => t('Main menu'),
+              'level' => 'h2',
+              'class' => array('element-invisible'),
+            ),
+          )); ?>
+        </nav>
+      <?php endif; ?>
+
 
       <?php print render($page['navigation']); ?>
 
     </div></div><!-- /.section, /#navigation -->
 
-    <?php print render($page['sidebar_first']); ?>
-
-    <?php print render($page['sidebar_second']); ?>
+    <?php
+      // Render the sidebars to see if there's anything in them.
+      $sidebar_first  = render($page['sidebar_first']);
+      $sidebar_second = render($page['sidebar_second']);
+    ?>
+
+    <?php if ($sidebar_first || $sidebar_second): ?>
+      <aside class="sidebars">
+        <?php print $sidebar_first; ?>
+        <?php print $sidebar_second; ?>
+      </aside><!-- /.sidebars -->
+    <?php endif; ?>
 
   </div></div><!-- /#main, /#main-wrapper -->
 
diff --git a/templates/region--footer.tpl.php b/templates/region--footer.tpl.php
new file mode 100644
index 0000000000000000000000000000000000000000..a76a2cb9c4b493052e2d4672a51fc7a33f2d15bf
--- /dev/null
+++ b/templates/region--footer.tpl.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * @file
+ * Zen theme's implementation to display a region.
+ *
+ * Available variables:
+ * - $content: The content for this region, typically blocks.
+ * - $classes: String of classes that can be used to style contextually through
+ *   CSS. It can be manipulated through the variable $classes_array from
+ *   preprocess functions. The default values can be one or more of the following:
+ *   - region: The current template type, i.e., "theming hook".
+ *   - region-[name]: The name of the region with underscores replaced with
+ *     dashes. For example, the page_top region would have a region-page-top class.
+ * - $region: The name of the region variable as defined in the theme's .info file.
+ *
+ * Helper variables:
+ * - $classes_array: Array of html class attribute values. It is flattened
+ *   into a string within the variable $classes.
+ * - $is_admin: Flags true when the current user is an administrator.
+ * - $is_front: Flags true when presented in the front page.
+ * - $logged_in: Flags true when the current user is a logged-in member.
+ *
+ * @see template_preprocess()
+ * @see template_preprocess_region()
+ * @see zen_preprocess_region()
+ * @see template_process()
+ */
+?>
+<?php if ($content): ?>
+  <footer id="footer" class="section <?php print $classes; ?>">
+    <?php print $content; ?>
+  </footer><!-- region--footer.tpl -->
+<?php endif; ?>
diff --git a/templates/region--sidebar.tpl.php b/templates/region--sidebar.tpl.php
index dd8d6110743c842d04b637bfec86b7e3986c4e81..265b7bea8ad009b89e076de7c7d2a407dd63f288 100644
--- a/templates/region--sidebar.tpl.php
+++ b/templates/region--sidebar.tpl.php
@@ -27,7 +27,7 @@
  */
 ?>
 <?php if ($content): ?>
-  <div class="<?php print $classes; ?>"><div class="section">
+  <section class="<?php print $classes; ?>"><div class="section">
     <?php print $content; ?>
-  </div></div><!-- region--sidebar.tpl -->
+  </div></section><!-- region--sidebar.tpl -->
 <?php endif; ?>