Here is the order in which events are raised during a document update:

• BeginUpdate()
• Insert() / Remove() / Replace()
• EndUpdate()

If the insert/remove/replace methods are called without a call to BeginUpdate(), they will call BeginUpdate() and EndUpdate() to ensure no change happens outside of UpdateStarted/UpdateFinished.

There can be multiple document changes between the BeginUpdate() and EndUpdate() calls. In this case, the events associated with EndUpdate will be raised only once after the whole document update is done.

The UndoStack listens to the UpdateStarted and UpdateFinished events to group all changes into a single undo step.