Shows you the history of a given task, such as when tags were changed, and when it was created.
History display is limited to only one task at a time.
You can also use history /search terms to save a step in getting the history of a task. If the search returns multiple tasks, then it'll show you the history of just the first.
Because history only shows you one task, saying just history alone will show you the first task in your context. See also help context.
Examples: