Although the castle is not particularly old for the local standards as it dates back to the mid-17th century, it was almost certainly erected in the location of the much more ancient Urartian fortress. According to Mehmed Top, the history of Hoşap goes back to the Kingdom of Urartu when it was a military stronghold, standing at the crossroads of two strategic roads. The area was later conquered by the Persians and then controlled by the Macedonian army of Alexander the Great. The usual succession of Seleucid, Roman, and Byzantine Empires followed. In the Medieval period, Hoşap was a part of the Kingdom of Vaspurakan, the biggest province of Greater Armenia, which later became an independent kingdom, centred around Lake Van.

The Turkish rule of the area began with the arrival of the Seljuks in the middle of the 11th century. After a period of the Ilkhanids control in the 13th century, Hoşap got into the hands of Kara Koyunlu tribe. These Black Sheep Turkomans, as this is the literal translation of their name, were a Muslim Oghuz Turkic tribal federation. They dominated the region encompassing today’s Azerbaijan, Armenia, northwestern Iran, eastern Turkey, and northeastern Iraq. One of their rulers, known as Kara Yusuf, offered the area of Hoşap to a Kurdish tribe of Mahmudis at the beginning of the 15th century. They established their emirate, formally dependant on Kara Koyunlu. When the Kara Koyunlu state collapsed in the second half of the 15th century, the Mahmudis continued their rule over Hoşap, under the rule of Ak Koyunlu (White Sheep) tribe, and later under the Safavid dynasty of Iran.

Hosap Castle During Ottoman–Safavid War, fought between 1532 and 1555, the Mahmudis supported the Ottomans, and thus earned numerous privileges. They continued their semi-independent rule of Hoşap and erected the magnificent castle that can be seen today. It was constructed by Sarı Süleyman Mahmudi, the chief of the Mahmudis tribe, in 1643. The Mahmudi beys used the castle well into the 19th century, until Tanzimat reforms reorganised the provincial administration of the Ottoman Empire.

Hosap Castle is sometimes also called Mahmudi Castle or Narin Castle, the last phrase ironically meaning Delicate Castle. It is the most important monument erected by the Mahmudis. Although the ornate inscription over the main gate gives the date of its erection as 1643, there is some evidence that it had existed earlier and was only renovated by Sarı Süleyman. In his paper devoted to the castle, Mehmed Top mentions that the reference to Kale-i Mahmudi had been made by Matrakçı Nasuh in the mid-16th century. Matrakçı Nasuh, of Bosnian origins, was a statesman of the Ottoman Empire, as well as a polymath, teacher, historian, cartographer, swordmaster, navigator, and inventor. As a miniaturist, he created four historic volumes of miniatures, and one of them, Fetihname-i Karabuğdan, deals with Suleyman the Magnificent war against the Safavids. He mentioned that he encountered Kale-i Mahmudi on the way back from the Persian campaign.

Another historical source concerning the castle is the ubiquitous Evliya Çelebi who travelled the territory of the Ottoman Empire and neighbouring lands over a period of forty years. He recorded his experiences in a travelogue called Seyahatname. Evliya Çelebi visited Hoşap in 1650 and left the detailed description of the castle: “it is on a high rock with the Hoşap River on the west. It is surrounded by low walls with forty bastions and two entrances but without a moat. It contains some eight hundred houses, a han, a hammam and several shops.”

The castle was damaged at least twice: for the first time during the siege by the Ottoman Beylerbeyi of Van in the 1650s, and for the second time in 1839, during the imposition of the Edict of Gülhane. This legal act abolished tax farming and eliminated the millet system where religiously based communities had operated autonomously.