The Persian word darkhana, is composed of two syllables, dar and khana. The preposition dar means in, and khana means house. Thus, the darkhana means in the house. Any specific thing in the house is also called darkhana. Another view suggests that it is derived from darb-i khana means chief place of residence, or dari khana, a residence with big windows being used for the royal meetings. In Ismaili terminology, it represents specific abode of the Imam, or Imam's headquarters.

In Arabian period of the Ismaili history, Mecca, known as haram amin (an inviolable and secure place) or balad al-amin (the protected city) was the birth place of the Prophet and Ali bin Abu Talib. Then, Medina became the seat of the first Imam Ali bin Abu Talib (d. 40/661), and then he moved to Kufa. Imam Hussain (d. 61/680) resided in Mecca, while Medina became residence of Imam Zayn al-Abidin (d. 94/713) until Imam Jafar Sadik (d. 148/765). It implies that both Medina and Kufa were early seats of the Imams. 

In Syrian period, Salamia was next foothold of Imam Ismail (d. 158/775), and continued to remain so, till the period of Imam Razi Abdullah (d. 268/881). It was however a dawr-i satr, the Imams had to travel in secret from one to another place, resulting their seat unsettled. Nevertheless, most of the Imams flourished in Salamia, making it their headquarters, then known as dar al-hijra (the land of refuge) according to the theory based on the example of the Prophet, who emigrated to Medina. The application of the term, dar al-hijra continued for a long period during pre-Fatimid, Fatimid and Alamut periods.

In North African and Egyptian periods, Imam al-Mahdi (d.322/934) left Salamia and travelled as far as Raqada in North Africa, where he founded the Fatimid Caliphate. Raqada, Mahdiya and Mansuriya were thus designated the next dar al-hijra from Imam al-Mahdi to Imam al-Muizz (d. 365/975). The seat of the Fatimid Imams then moved to Cairo till the period of Imam al-Mustansir billah I (d. 487/1095) and Imam al-Nizar (d. 490/1097).

The next headquarters of the Imam flourished in the fort of Alamut during the time of Imam al-Hadi (d. 530/1136), which remained continued till the period of Imam Ruknuddin Khairshah (d. 655/1257). Alamut was also called Baldat al-Iqbal (the city of good fortune)

In post-Alamut period, Azerbaijan was made next seat of Imam Shamsuddin Muhammad (d. 710/1310) to Imam Kassim Shah (d. 771/1370). Later, Imam Islam Shah (d. 827/1423) appeared on the horizon of Kahek in Iran in 799/1396, which was the first seat in Iran in post-Alamut period, an abode of emigration and congregation.

Henceforward, the dar al-hijra came to be replaced by different terms coined in the Pandiyat-i Jawanmardi, such as darbar-i astan-i mubarak, darbar-i Imam-i Zaman, darbar-i Imam-i waqt, darbar-i Mawlana and dargah-i Imam-i Zaman. The Indian Ismaili Pirs used the word dargah for the headquarters of the Imams.

The word dargah meaning court, literally seat was however a term in vogue in the India. Thus, the visitor of the dargah was called dagahi or the pilgrim of the dargah. In those days, the term dargah became confined to the shrine in Iran and India, therefore, the word darkhana came in usage for the seat of the Imams. The word darkhana means royal palace or court. Literally, the darkhana means seat or headquarters. The Syrian Ismailis called it al-markaz.

Imam Mustansir billah II (d. 880/1475) also made his seat in Kahek and Shah-i Babak. Anjudan was next dargah or darkhana from Imam Gharib Mirza (d. 902/1496) to Imam Khalilullah Ali I (d. 993/1585). The Syrian Ismailis called Anjudan as "the abode of the faithful" (dar al-mu'minin). Kahek, Shahr-i Babak were the next seats, regularly frequented by the followers. Imam Khalilullah II (d. 1233/1817) first made Mahallat, then Yazd as his headquarters. Imam Hasan Ali Shah (d. 1298/1881) left Iran in 1842 and arrived in Sind and declared Jerruk as his seat or the darkhana in 1843. In 1848, Imam Hasan Ali Shah made Bombay as the darkhana.

We have summed up that Medina, Kufa, Salamia, Raqada, Mahdiya, Mansuriya, Cairo, Alamut, Kahek, Shahr-i Babak, Anjudan, Mahallat, Yazd, Jerruk and Bombay exercised role of the darkhana, where the Imams resided and graced audience to the followers. 

Imam Sultan Muhammad Shah (d. 1376/1957) was an international personality, and it required him to travel abroad from time to time. He resided in Bombay between 1885 and 1907, then transferred his residence in Europe. In those days, the travelling expense was not affordable and not possible for the followers to throng in Europe to behold the Imam, therefore, Imam himself began to travel in India, Burma, Ceylon and East Africa to grace the didar. 

The Khadak Jamatkhana, Bombay became thus a symbol of darkhana of the past. It was followed by Nairobi and Dar-es-Salaam. Presently, the following eight Jamatkhanas in different countries play the role of the principal and darkhana Jamatkhana:-

1. India : Khadak Jamatkhana, Bombay.

2. Kenya : Parklands Jamatkhana, Nairobi.

3. Tanzania : Mosque Street, Dar-es-Salaam.

4. Uganda : Namirembe Road, Old Kampala.

5. Pakistan : Garden East, Karachi.

6. Portugal : Avenida Lusiade, Lisbon. 

7. England : Cromwell Gardens, London.

8. Canada : Burnaby