The classical Kurdish story of Mem and Zin (which I'm reading online in Salah Saadalla's translation) appears to be set in a principality called Botan, whose prince (Zin's brother) rules from the town of Jizir:
His throne was in Jizir19 and his star was rising
His luck was strong and his position was praisworthy
He ruled over the Turk, the Arab and the Persian
He was famous as the Prince of Botan
19 Jizir: the capital of the principality of Botan. Now a town in South East Turkey.
Now I've tried to search for Jizir and Botan, but the only references I've found online have been back to the story of Mem and Zin, or like this article to other pieces of Kurdish literature ("The land of Jizir and Botan, which is the land of Kurdistan").
What is the setting of Mem and Zin? Was Botan a real Kurdish principality, and if so where and when? Or is it something invented for the story, a fictional Kurdish nation to instil pride in Kurdish listeners?