"The word taj is a Persian loanword in Arabic, which is derived from the old Persian tag, meaning crown. It is said that Dahhak was the first to wear the crown in the world. According to the hadith, "The turbans are the crowns of the Arabs" (al-ama'im tijan al-arab).
The term taj is not used in the early descriptions of the Fatimid ceremonies. Musabbih (d. 420/1029) invariably used the term imama. The Fatimid taj was a turban (imama) wound in a distinctive fashion. It was called a noble crown (al-taj al-sharif) and the winding of majesty (shaddat al-waqar). It was surmounted by a solitaire (al-yatima). The servant who wound this turban was called the winder of the crown (shaddal taj). Mostly, the turban was ornamented with sapphires, emeralds and the jewels that adorned the top of the turban. The turban was made of a length of cloth wound around the head with one end or tail left hanging down.
The Fatimid Imams wore the taj on ceremonial occasions (mawakib) on the great fest-days. They did not wear a proper crown but a turban richly studded with gems, including a particularly large one called al-yatima, weighing seven dhirams, of colour, for the elaborate winding of which a special official (shadd a-taj al-sharif) was appointed.
During the annual majalis in Poona in 1920, Imam Sultan Muhammad Shah told to the Volunteers of Bombay, who were on duty, to come to his bungalow in Bombay and he would bestow them coat-of-arms (taj) to be worn on the volunteers' caps. After the majalis in Poona, the officers of the Volunteer Corps went to the bungalow in Bombay, where they were presented two gifts by the Imam: one was the coat-of-arms (taj) and the second was the rare photograph of the Imam. Since then, the taj began to be affixed on the caps of the volunteers and also in all community affairs.
The tradition of the taj as an emblem is retained with the Ismailis. If one looks at the Ismaili taj, he will observe that a long strip starts from bottom of right side and is turned in circle on upper side, then it spread to the left side. Thus, the right side is shorter from above, but longer at bottom wherefrom it started, and the left side is higher from upper side, and shorter at bottom where it ends. The whole circle makes the design of two eyes. In the middle of upper side, there is one tura, which in other words is set up between two eyes, spreading the upper right side.
It is related that on June 13, 1945, the Imam graced a didar to Bombay jamat at the Aga Khan Club at 10 a.m. On that night, he visited the illuminated and well decorated streets of the Ismaili locations with the Begum and Varas Fateh Ali Dhala at 9 p.m. His car reached at dharkhana Jamatkhana's street. The building of Jamatkhana was fully illuminated with multi-coloured lights. The Imam saw a calligraphical design on the door of the Jamatkhana, and said to his Begum, "This is an Arabian art." He then came at the main square of Sa'lim Road and came out of his car and watched a well designed mihrab erected there. He called for the painter and blessed him and said, "This taj was worn by my ancestors during the rule of Fatimid Caliphate in Egypt."