diff --git a/pelicanconf.py b/pelicanconf.py
index 40b578b..424f4cb 100644
--- a/pelicanconf.py
+++ b/pelicanconf.py
@@ -41,9 +41,12 @@ PLUGIN_PATHS = ["plugins"]
 PLUGINS = [
     'i18n_subsites',
     "pelican-page-hierarchy",
+    "always_modified",
     # 'pdf-img',
 ]
 
+ALWAYS_MODIFIED = True
+
 # Mirror source structure
 PATH_METADATA = '(?P<path_no_ext>.*)\..*'
 ARTICLE_URL = ARTICLE_SAVE_AS = PAGE_URL = PAGE_SAVE_AS = '{path_no_ext}.html'
diff --git a/plugins/__init__.py b/plugins/__init__.py
new file mode 100644
index 0000000..1fd5e14
--- /dev/null
+++ b/plugins/__init__.py
@@ -0,0 +1 @@
+from .always_modified import *
diff --git a/plugins/always_modified.py b/plugins/always_modified.py
new file mode 100644
index 0000000..0f2578b
--- /dev/null
+++ b/plugins/always_modified.py
@@ -0,0 +1,20 @@
+"""
+If "modified" date/time is not defined in article metadata, fall back to the "created" date.
+"""
+
+from pelican import signals
+from pelican.contents import Content, Article
+
+def add_modified(content):
+    if not isinstance(content, Article):
+        return
+    
+    if not content.settings.get('ALWAYS_MODIFIED', False):
+        return
+
+    if hasattr(content, 'date') and not hasattr(content, 'modified'):
+        content.modified = content.date
+        content.locale_modified = content.locale_date
+    
+def register():
+    signals.content_object_init.connect(add_modified)
diff --git a/plugins/always_modified/README.md b/plugins/always_modified/README.md
new file mode 100644
index 0000000..585e67b
--- /dev/null
+++ b/plugins/always_modified/README.md
@@ -0,0 +1,14 @@
+# Always Modified
+
+Say you want to sort by modified date/time in a theme template, but not all
+your articles have modified date/timestamps explicitly defined in article
+metadata. This plugin facilitates that sorting by assuming the modified date
+(if undefined) is equal to the created date.
+
+## Usage
+
+1. Add `ALWAYS_MODIFIED = True` to your settings file.
+2. Now you can sort by modified date in your templates:
+
+    {% for article in articles|sort(reverse=True,attribute='modified') %}
+
diff --git a/theme/templates/index.html b/theme/templates/index.html
index 82152b7..4f4e424 100644
--- a/theme/templates/index.html
+++ b/theme/templates/index.html
@@ -2,7 +2,7 @@
 
 {% block content %}
 
-{% for article in articles_page.object_list %}
+{% for article in articles_page.object_list | sort(reverse=True,attribute='modified') %}
 <article>
   <header>
     <h2><a href="{{ SITEURL }}/{{ article.url }}{% if not DISABLE_URL_HASH %}#{{ article.slug }}{% endif %}">{{ article.title }}</a></h2>