Anatolia
The peninsula after Manzikert, which took four hundred years to stop being contested. A Seljuk branch organised the plateau and was broken by the Mongols; the marches it could no longer hold filled with Turkmen principalities; Greek and Armenian states survived on the coasts and in the mountains, one of them outlasting Constantinople itself. The polity that eventually took all of it began as the smallest of the principalities and is the reason the rest are usually left out.
The line below is a time axis. Position on it is date, so concurrency is visible: concurrent polities sit side by side rather than in sequence.
15 sourced edges run between this region and another, to Great Seljuk Empire, Ilkhanate, Byzantine Empire, Mamluk Sultanate, Crimean Khanate, Roman Empire, Abbasid Caliphate of Cairo, Hafsid Sultanate, Bagratid Armenia, Serbia, Second Bulgarian Empire, Ak Koyunlu and Zayyanid Kingdom of Tlemcen. Those are not drawn on this line — a thread that crossed regions would assert a sequence nobody cited — but they are on each polity’s own page.