Khoy County () is in West Azerbaijan province, Iran. The capital of the county is the city of Khoy. At the 2006 census, the county's population was 365,573 in 85,550 households. The following census in 2011 counted 354,309 people in 96,367 households, by which time Chaypareh District had been separated from the county to form Chaypareh County. At the 2016 census, Khoy County's population was 348,664 in 101,130 households. Administrative divisions The population history and structural changes of Khoy County's administrative divisions over three consecutive censuses are shown in the following table. The latest census shows four districts, 11 rural districts, and six cities. History Khoy was named in ancient times for the salt mines that made it an important spur of the Silk Route. 3000 years ago, a city had existed on the area where Khoy is located nowadays, but its name became Khoy only from 14 centuries ago. In 714 BC, Sargon II passed the region of which Khoy is part of in a campaign against Urartu. In the Parthian period, Khoy was the gateway of the Parthian Empire in the Northwest. Around 37 BC, Marc Anthony had crossed the plain that is located between Khoy and Marand during one of the many and frequent Roman-Parthian Wars. One of the important historic elements of the city's Khoy in the county is the St. Sourp Sarkis church, one of the many churches in the county. Armenian documents wrote that the date of the making has to be either 332 or 333 AD. In the city of Khoy and its surrounding villages, churches are seen and it is reported that Armenians have always been comprising a significant amount of the city's population, but the city was never an "Armenian city" (as in comprising a vast majority). Modern period Khoy city was fortified at various times in its history, most recently by the Qajar dynasty in the nineteenth century. After the death of Nadir Shah Afshar in 1747, Khoy and its immediate surroundings broke away from central government of Iran like several other regions of Iran, including what is now Georgia and some of the northern Caucasian Khanates comprising the northwestern territories of Iran. Khoy became the centre of the newly established Khanate of Khoy (1747–1813) which was loyal to the central government only when it was powerful (like during Karim Khan's reign), and autonomous when the central role was weak.