diff --git a/src/test/test_helpers/test_helpers.js b/src/test/test_helpers/test_helpers.js
index f51dc3566..cd28afc72 100644
--- a/src/test/test_helpers/test_helpers.js
+++ b/src/test/test_helpers/test_helpers.js
@@ -21,6 +21,8 @@ export const testGroup = function (name, options, callback) {
   }
 
   const beforeEach = async () => {
+    window.onbeforeunload = () => {} // Inhibit Chrome page reload errors in testing
+
     // Ensure window is active on CI so focus and blur events are natively dispatched
     window.focus()
 
@@ -33,6 +35,8 @@ export const testGroup = function (name, options, callback) {
   }
 
   const afterEach = () => {
+    window.onbeforeunload = null
+
     if (template != null) setFixtureHTML("")
     return teardown?.()
   }
diff --git a/src/trix/config/text_attributes.js b/src/trix/config/text_attributes.js
index 8ac432a73..c727912fa 100644
--- a/src/trix/config/text_attributes.js
+++ b/src/trix/config/text_attributes.js
@@ -27,6 +27,16 @@ export default {
       }
     },
   },
+  target: {
+    groupTagName: "a",
+    parser(element) {
+      const matchingSelector = `a:not(${attachmentSelector})`
+      const link = element.closest(matchingSelector)
+      if (link) {
+        return link.getAttribute("target")
+      }
+    },
+  },
   strike: {
     tagName: "del",
     inheritable: true,
diff --git a/src/trix/controllers/toolbar_controller.js b/src/trix/controllers/toolbar_controller.js
index a1178fea7..3d62b8003 100644
--- a/src/trix/controllers/toolbar_controller.js
+++ b/src/trix/controllers/toolbar_controller.js
@@ -9,15 +9,19 @@ const dialogSelector = "[data-trix-dialog]"
 const activeDialogSelector = `${dialogSelector}[data-trix-active]`
 const dialogButtonSelector = `${dialogSelector} [data-trix-method]`
 const dialogInputSelector = `${dialogSelector} [data-trix-input]`
-const getInputForDialog = (element, attributeName) => {
-  if (!attributeName) { attributeName = getAttributeName(element) }
-  return element.querySelector(`[data-trix-input][name='${attributeName}']`)
+const getInputForDialog = (element, dialogName, attributeName) => {
+  const name = dialogName === attributeName ? dialogName : `${dialogName}[${attributeName}]`
+  return element.querySelector(`[data-trix-input][name='${name}']`)
 }
 const getActionName = (element) => element.getAttribute("data-trix-action")
 const getAttributeName = (element) => {
-  return element.getAttribute("data-trix-attribute") || element.getAttribute("data-trix-dialog-attribute")
+  return element.getAttribute("data-trix-attribute")
 }
 const getDialogName = (element) => element.getAttribute("data-trix-dialog")
+const getDialogAttributeNames = (element) => {
+  return (element.getAttribute("data-trix-dialog-attribute") ||
+    element.getAttribute("data-trix-dialog-attributes")).split(" ")
+}
 
 export default class ToolbarController extends BasicObject {
   constructor(element) {
@@ -94,7 +98,7 @@ export default class ToolbarController extends BasicObject {
       event.preventDefault()
       const attribute = element.getAttribute("name")
       const dialog = this.getDialog(attribute)
-      this.setAttribute(dialog)
+      this.setAttributes(dialog)
     }
     if (event.keyCode === 27) {
       // Escape key
@@ -190,37 +194,67 @@ export default class ToolbarController extends BasicObject {
       disabledInput.removeAttribute("disabled")
     })
 
-    const attributeName = getAttributeName(element)
-    if (attributeName) {
-      const input = getInputForDialog(element, dialogName)
+    const attributeNames = getDialogAttributeNames(element)
+    for (const attributeName of attributeNames) {
+      const input = getInputForDialog(element, dialogName, attributeName)
       if (input) {
-        input.value = this.attributes[attributeName] || ""
-        input.select()
+        switch (input.type) {
+          case "checkbox":
+            input.checked = this.attributes[attributeName] === input.value
+            break
+          default:
+            input.value = this.attributes[attributeName] || ""
+            input.select()
+        }
       }
     }
 
     return this.delegate?.toolbarDidShowDialog(dialogName)
   }
 
-  setAttribute(dialogElement) {
-    const attributeName = getAttributeName(dialogElement)
-    const input = getInputForDialog(dialogElement, attributeName)
-    if (input.willValidate && !input.checkValidity()) {
-      input.setAttribute("data-trix-validate", "")
-      input.classList.add("trix-validate")
-      return input.focus()
-    } else {
-      this.delegate?.toolbarDidUpdateAttribute(attributeName, input.value)
-      return this.hideDialog()
+  setAttributes(dialogElement) {
+    const dialogName = getDialogName(dialogElement)
+    const attributeNames = getDialogAttributeNames(dialogElement)
+
+    for (const attributeName of attributeNames) {
+      const input = getInputForDialog(dialogElement, dialogName, attributeName)
+
+      if (input.willValidate && !input.checkValidity()) {
+        input.setAttribute("data-trix-validate", "")
+        input.classList.add("trix-validate")
+        input.focus()
+      } else {
+        switch (input.type) {
+          case "checkbox":
+            if (input.checked) {
+              this.delegate?.toolbarDidUpdateAttribute(attributeName, input.value)
+            } else {
+              this.delegate?.toolbarDidRemoveAttribute(attributeName)
+            }
+            break
+          default:
+            this.delegate?.toolbarDidUpdateAttribute(attributeName, input.value)
+        }
+      }
     }
+
+    this.hideDialog()
   }
 
-  removeAttribute(dialogElement) {
-    const attributeName = getAttributeName(dialogElement)
-    this.delegate?.toolbarDidRemoveAttribute(attributeName)
+  setAttribute(dialogElement) { this.setAttributes(dialogElement) }
+
+  removeAttributes(dialogElement) {
+    const attributeNames = getDialogAttributeNames(dialogElement)
+
+    for (const attributeName of attributeNames) {
+      this.delegate?.toolbarDidRemoveAttribute(attributeName)
+    }
+
     return this.hideDialog()
   }
 
+  removeAttribute(dialogElement) { this.removeAttributes(dialogElement) }
+
   hideDialog() {
     const element = this.element.querySelector(activeDialogSelector)
     if (element) {
diff --git a/src/trix/models/html_sanitizer.js b/src/trix/models/html_sanitizer.js
index 3dd0b3e68..19df347c5 100644
--- a/src/trix/models/html_sanitizer.js
+++ b/src/trix/models/html_sanitizer.js
@@ -2,7 +2,7 @@ import BasicObject from "trix/core/basic_object"
 
 import { nodeIsAttachmentElement, removeNode, tagName, walkTree } from "trix/core/helpers"
 
-const DEFAULT_ALLOWED_ATTRIBUTES = "style href src width height language class".split(" ")
+const DEFAULT_ALLOWED_ATTRIBUTES = "style href target src width height language class".split(" ")
 const DEFAULT_FORBIDDEN_PROTOCOLS = "javascript:".split(" ")
 const DEFAULT_FORBIDDEN_ELEMENTS = "script iframe form noscript".split(" ")
 
diff --git a/src/trix/views/piece_view.js b/src/trix/views/piece_view.js
index c03d6c266..6d7a70cc4 100644
--- a/src/trix/views/piece_view.js
+++ b/src/trix/views/piece_view.js
@@ -111,17 +111,24 @@ export default class PieceView extends ObjectView {
   }
 
   createContainerElement() {
+    const attributes = {}
+    let groupTagName
+
     for (const key in this.attributes) {
       const value = this.attributes[key]
       const config = getTextConfig(key)
       if (config) {
         if (config.groupTagName) {
-          const attributes = {}
-          attributes[key] = value
-          return makeElement(config.groupTagName, attributes)
+          groupTagName = groupTagName || config.groupTagName
+
+          if (config.groupTagName === groupTagName) {
+            attributes[key] = value
+          }
         }
       }
     }
+
+    if (groupTagName) { return makeElement(groupTagName, attributes) }
   }
 
   preserveSpaces(string) {