Making a Useful Notes Page on a historical city

Hello, I want to make a useful notes page on Istanbul during its Roman and Ottoman eras. The modern city has a page with some notes on its past, but I want to make a page on historical Constantinople. (Obviously, it'll be called Useful Notes: Constantinople to distinguish it from the Istanbul article).

I thought about adding sections (Roman, Ottoman, etc) to the Istanbul article, but I worry the page might get much too long. Is there any place I need to have the article cleared before just creating the page? And is there anything else that I should know?

You may use Trope Launch Pad (despite the name, it can be used for more than just tropes) to draft your article and get feedback on it. Just remember that Useful Notes articles are not there to act like an encyclopedia and fully document the history of a subject. We can let Wikipedia handle that. Rather, their purpose is to correct common misconceptions that writers have about their subjects and provide a guide for accurate writing.