diff --git a/jinja2/exceptions.py b/jinja2/exceptions.py
index 147ddb9..154cf44 100644
--- a/jinja2/exceptions.py
+++ b/jinja2/exceptions.py
@@ -14,16 +14,6 @@
     """Baseclass for all template errors."""
 
 
-class UndefinedError(TemplateError):
-    """Raised if a template tries to operate on :class:`Undefined`."""
-
-
-class SecurityError(TemplateError):
-    """Raised if a template tries to do something insecure if the
-    sandbox is enabled.
-    """
-
-
 class TemplateNotFound(IOError, LookupError, TemplateError):
     """Raised if a template does not exist."""
 
@@ -37,9 +27,16 @@
 
     def __init__(self, message, lineno, name=None, filename=None):
         if name is not None:
-            extra = '%s, line %d' % (name, lineno)
+            extra = '%s, line %d' % (name.encode('utf-8'), lineno)
         else:
             extra = 'line %d' % lineno
+        # if the message was provided as unicode we have to encode it
+        # to utf-8 explicitly
+        if isinstance(message, unicode):
+            message = message.encode('utf-8')
+        # otherwise make sure it's a in fact valid utf-8
+        else:
+            message = message.decode('utf-8', 'ignore').encode('utf-8')
         TemplateError.__init__(self, '%s (%s)' % (message, extra))
         self.message = message
         self.lineno = lineno
@@ -50,15 +47,28 @@
 class TemplateAssertionError(TemplateSyntaxError):
     """Like a template syntax error, but covers cases where something in the
     template caused an error at compile time that wasn't necessarily caused
-    by a syntax error.
+    by a syntax error.  However it's a direct subclass of
+    :exc:`TemplateSyntaxError` and has the same attributes.
     """
 
 
 class TemplateRuntimeError(TemplateError):
-    """A runtime error."""
+    """A generic runtime error in the template engine.  Under some situations
+    Jinja may raise this exception.
+    """
 
 
-class FilterArgumentError(Exception):
+class UndefinedError(TemplateRuntimeError):
+    """Raised if a template tries to operate on :class:`Undefined`."""
+
+
+class SecurityError(TemplateRuntimeError):
+    """Raised if a template tries to do something insecure if the
+    sandbox is enabled.
+    """
+
+
+class FilterArgumentError(TemplateRuntimeError):
     """This error is raised if a filter was called with inappropriate
     arguments
     """