diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/Core/Entity/Term.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/Core/Entity/Term.php
index ec75f35..d85f200 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/Core/Entity/Term.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/Core/Entity/Term.php
@@ -80,6 +80,7 @@ public function getName() {
    * {@inheritdoc}
    */
   public function getParents() {
+
     $parents = array();
     foreach ($this->get('parent') as $parent) {
       $parents[] = $parent->value;
@@ -90,6 +91,26 @@ public function getParents() {
   /**
    * {@inheritdoc}
    */
+  public function getSoleParent() {
+    $parents = $this->getParents();
+    if (count($parents) == 1) {
+      return $parents[0];
+    }
+    else {
+      return FALSE;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasParents() {
+    return count($this->getParents() != 0);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getWeight() {
     return $this->get('weight')->value;
   }
@@ -118,8 +139,23 @@ public function setName($name) {
   /**
    * {@inheritdoc}
    */
-  public function setParent($parent) {
-    return $this->set('parent', $parent);
+  public function clearParents() {
+    return $this->set('parent', array());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addParents($parents) {
+
+    if (!is_array($parents)) {
+      $parents = array($parents);
+    }
+
+    $current_parents = $this->getParents();
+
+    return $this->set('parent', array_merge($parents, $current_parents));
+
   }

   /**
@@ -171,7 +207,7 @@ public static function postDelete(EntityStorageControllerInterface $storage_cont
   public function postSave(EntityStorageControllerInterface $storage_controller, $update = TRUE) {
     // Only change the parents if a value is set, keep the existing values if
     // not.
-    if (count($this->getParents())) {
+    if ($this->hasParents()) {
       $storage_controller->deleteTermHierarchy(array($this->id()));
       $storage_controller->updateTermHierarchy($this);
     }
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/TermInterface.php b/core/modules/taxonomy/lib/Drupal/taxonomy/TermInterface.php
index f5572d6..12dd4d8 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/TermInterface.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/TermInterface.php
@@ -47,6 +47,24 @@ public function getName();
   public function getParents();

   /**
+   * If this term has exactly one parent, returns the parent's tid,
+   * otherwise returns FALSE.
+   *
+   * @return int|FALSE
+   *   The tid of the parent or FALSE.
+   */
+  public function getSoleParent();
+
+  /**
+   * Returns TRUE is this term has parents. Returning FALSE indicates
+   * that this is a top-level term.
+   *
+   * @return boolean
+   *   TRUE if term has parents, FALSE if it has no parents.
+   */
+  public function hasParents();
+
+  /**
    * Returns the weight of this term.
    *
    * @return int
@@ -85,14 +103,21 @@ public function setFormat($format);
   public function setName($name);

   /**
-   * Returns the parent term(s) for this term.
+   * Adds parents to this term.
    *
-   * @param int $weight
-   *   The term's parent
-   * @return int
-   *   The parent term
+   * @param mixed $parent
+   *   A tid or array of tids to add to the list of parent terms
+   *   for this term.
+   * @return void
+   */
+  public function addParents($parents);
+
+  /**
+   * Removes any parents from this term
+   *
+   * @return void
    */
-  public function setParent($parent);
+  public function clearParents();

   /**
    * Returns the weight of this term.
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/TermStorageController.php b/core/modules/taxonomy/lib/Drupal/taxonomy/TermStorageController.php
index cb0821c..85a28b9 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/TermStorageController.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/TermStorageController.php
@@ -17,6 +17,20 @@
 class TermStorageController extends DatabaseStorageControllerNG implements TermStorageControllerInterface {

   /**
+   * Attempt to load the term parents
+   *
+   * {@inheritdoc}
+   */
+  protected function attachLoad(&$terms, $load_revision = FALSE) {
+    parent::attachLoad($terms, $load_revision);
+    foreach($terms as $idx => $term) {
+      $parents = array_keys(taxonomy_term_load_parents($term->id()));
+      $term->parent->setValue($parents);
+      $terms[$idx] = $term;
+    }
+  }
+
+  /**
    * Overrides Drupal\Core\Entity\DatabaseStorageController::create().
    *
    * @param array $values
diff --git a/core/modules/taxonomy/taxonomy.admin.inc b/core/modules/taxonomy/taxonomy.admin.inc
index 274e30e..02c3bcd 100644
--- a/core/modules/taxonomy/taxonomy.admin.inc
+++ b/core/modules/taxonomy/taxonomy.admin.inc
@@ -178,7 +178,7 @@ function taxonomy_overview_terms($form, &$form_state, Vocabulary $vocabulary) {
         '#type' => 'hidden',
         // Yes, default_value on a hidden. It needs to be changeable by the
         // javascript.
-        '#default_value' => $term->getParents(),
+        '#default_value' => $term->getSoleParent(),
         '#attributes' => array(
           'class' => array('term-parent'),
         ),
@@ -329,12 +329,12 @@ function taxonomy_overview_terms_submit($form, &$form_state) {
   $weight = 0;
   $term = $tree[0];
   while ($term->id() != $form['#first_tid']) {
-    if (count($term->getParents()) == 0 && $term->getWeight() != $weight) {
+    if (!count($term->getParents()) && $term->getWeight() != $weight) {
       $term->setWeight($weight);
       $changed_terms[$term->id()] = $term;
     }
     $weight++;
-    $hierarchy = count($term->getParents()) != 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
+    $hierarchy = count($term->getParents()) == 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
     $term = $tree[$weight];
   }

@@ -350,15 +350,16 @@ function taxonomy_overview_terms_submit($form, &$form_state) {
       }
       // Terms not at the root level can safely start from 0 because they're all on this page.
       elseif ($values['term']['parent'] > 0) {
-        $level_weights[$values['term']['parent']] = isset($level_weights[$values['term']['parent']]) ? $level_weights[$values['term']->getParent()] + 1 : 0;
+        $level_weights[$values['term']['parent']] = isset($level_weights[$values['term']['parent']]) ? $level_weights[$values['term']['parent']] + 1 : 0;
         if ($level_weights[$values['term']['parent']] != $term->getWeight()) {
           $term->setWeight($level_weights[$values['term']['parent']]);
           $changed_terms[$term->id()] = $term;
         }
       }
       // Update any changed parents.
-      if ($values['term']['parent'] != $term->getParent()) {
-        $term->setParent($values['term']['parent']);
+      if ($values['term']['parent'] != $term->getSoleParent()) {
+        $term->clearParents();
+        $term->addParents($values['term']['parent']);
         $changed_terms[$term->id()] = $term;
       }
       $hierarchy = count($term->getParents()) == 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
@@ -373,7 +374,7 @@ function taxonomy_overview_terms_submit($form, &$form_state) {
       $term->setWeight($weight);
       $changed_terms[$term->id()] = $term;
     }
-    $hierarchy = $term->setParent() != 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
+    $hierarchy = count($term->getParents()) == 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
   }

   // Save all updated terms.
diff --git a/core/modules/taxonomy/taxonomy.module b/core/modules/taxonomy/taxonomy.module
index c21b665..96952b3 100644
--- a/core/modules/taxonomy/taxonomy.module
+++ b/core/modules/taxonomy/taxonomy.module
@@ -716,9 +716,7 @@ function taxonomy_get_tree($vid, $parent = 0, $max_depth = NULL, $load_entities
           $term = clone $term;
         }
         $term->depth = $depth;
-        unset($term->parent);
         $tid = $load_entities ? $term->id() : $term->tid;
-        $term->parents = $parents[$vid][$tid];
         $tree[] = $term;
         if (!empty($children[$vid][$tid])) {
           $has_children = TRUE;