Daylam

Daylam is a historic region in northern Iran along the southern coast of the Caspian Sea. The core area lies in the Alborz mountains and their foothills, with the broader zone stretching into parts of present-day Gilan, Qazvin and Mazandaran provinces. The landscape is rugged and forested, with valleys and highlands that shaped local society and defense strategies.

The Daylami, also written Daylamites, were an Iranian people who inhabited Daylam. They spoke Daylamite languages, a branch of Northwestern Iranian, now largely extinct but influential in toponymy and personal names. In classical sources, the Daylam were recognized for their martial culture and mountain-based independence, traits that persisted through medieval times.

From late antiquity into the early medieval period, Daylami communities played a pivotal role in the broader Iranian world. They supplied skilled cavalry and administrators to larger Iranic polities and were instrumental in the rise of the Buyid dynasty, a Daylamite-backed Shia dynasty that controlled much of Iran and Iraq in the 10th and 11th centuries. Daylamite soldiers and leaders also influenced later dynasties and the military culture of the region, contributing to the Persianate court culture despite their relatively remote homeland.

In the modern era, Daylam no longer exists as an administrative unit. The region is today part of several Iranian provinces, with toponyms such as Deylaman preserving the historical name. The Daylaman area remains known for its mountainous scenery and rural communities, and the term Daylam is primarily used in historical and linguistic contexts.