Daylam (sometimes Daylaman, Dailam or Delam) was a province of Persia, now part of Gīlān, Iran.
The Daylam region corresponds to the modern region of Gīlān.[1] It was the place of origin of the Buyid dynasty.
They had a prominent position during the Sassanid dynasty, their presence extended to Mesopotamia.
They were known to live in Northern Iran For more on its history, see the article on Gīlān.