Whenever your thesis statement is visible at the end of the (introductory) paragraph
Explanation:
Usually your thesis statement is a combination of the introductory paragraph, or basically just re-iterating what your topic will be about. Some schools don't teach thesis statements the same way as others do. If that is the case, make sure your ending is clear and worded precisely. You are transittioning to the next paragraph, so also make sure your sentences flow into the next paragraph. Hope this helped! :)
The rise of the Eastern Empire. The fate of Western Rome was ... At its height, the Roman Empire stretched from the Atlantic Ocean all the ... Being the Roman emperor had always been a particularly dangerous job, but during the tumultuous second and third centuries it nearly became a death sentence.