Gilan Province is one of the 31 provinces of Iran. It lies along the Caspian Sea, just west of the province of Mazandaran, east of the province of Ardabil, north of the provinces of Zanjan and Qazvin. The northern part of the province is part of territory of South (Iranian) Talesh. At the center of the province is the main city of Rasht. Other towns in the

province include Astara, Astaneh-e Ashrafiyyeh, Fuman, Lahijan, Langrud, Masooleh, Manjil, Rudbar, Roudsar, Shaft, Talesh, and Soumahe Sara.

The main harbor port of the province is Bandar-e Anzali (previously Bandar-e Pahlavi).

The first recorded encounter between Gilak and Deylamite warlords and invading Muslim Arab armies was at the Battle of Jalula in 637 AD. Deylamite commander Muta led an army of Gils, Deylamites, Azerbaijanis and people of the Rey region. Muta was killed in the battle and his defeated army managed to retreat in an orderly manner.

However, this victory appears to have been a Pyrrhic victory for the Arabs, since they did not pursue their opponents. Muslim Arabs never managed to conquer Gilan. Gilaks and Deylamites successfully repulsed all Arab attempts to occupy their land or to convert them to Islam. In fact, it was the Deylamites under the Buyid king Mu'izz al-Dawlah who finally shifted the power by conquering Baghdad in 945. Mu'izz al-Dawlah however allowed the Abbasid caliphs to remain in comfortable but secluded captivity in their palaces.