The word jubilee is derived from the Hebrew yobel, meaning ram’s horn. In the ancient time, the jubilee was announced by the blowing of the shofar, a trumpet of ram’s horn, and as a result, the occasion came to be known as yobel, or jubilee. The Arabic word for jubilee is also yobel, and Turkish ellinci. Jubilee is a momentous occasion, denoting the celebration of a period of time, anniversary or other special occasions.

It was initially pronounced as 'dimund 'joobu`lee, meaning “an anniversary celebrating the passage of 60 years.” Sixty years of Imam Sultan Muhammad Shah’s benevolent rule gave his followers a chance to celebrate the Diamond Jubilee by weighing him against diamonds. On December 31, 1945, the Imam had said to the H.H. The Aga Khan’s Legion Central Committee that, “Sixty years have been passed to the enthronement of the Imamate, which is its unique occasion. It is an incomparable occasion in the world. No occasion ever occurred in the world history like it.” The weighing ceremony was performed in Bombay at the Brabourne Stadium on the after-noon of Sunday, 10th March, 1946.

Over 100,000 Ismailis from various parts of the world had come to see this magnificent spectacle unusual event. The huge multitude present in the ceremony included fourteen ruling princes, among them the Maharajas of Kashmir and Baroda and the Jam Saheb of Nawanagar. The value of the diamonds was 640,000 British pounds.

The second jubilee was celebrated in the sports ground of the Aga Khan Club in at Dar-es-Salaam on 10th August, 1946. It was attended by 70,000 Ismailis, including the Governors of Kenya, Tanganyika and Uganda. This time the value of the diamonds was 684,000 British pounds. The sum value of the diamonds at each place was presented as an absolute gift to the Imam from his jubilant followers. This vast sum was again invested by him in a trust meant to enrich the life of the community in the educational and commercial spheres.

In a message to “Diamond Jubilee Souvenir Year Book,” the Imam said, “The Ismailia history has passed through several stages of development. My Diamond Jubilee marks such a stage in the present times. With it a phase of consolidation and cooperation has been achieved among my spiritual children in various countries, and now lies ahead a period of goodwill and expansion. With the Diamond Jubilee dawns a new era, full of hopes and opportunities for economics, educational, social and religious uplift of my beloved spiritual children all over the world. It is a time to go ahead and leave a mark on the world history like the glorious Ismailis of the past. Let the Diamond Jubilee message for my spiritual children be that of doing their best and devoting their best in the best cause of their beloved faith.”