It was a shrine with a tall blue dome
Little can be said about the ruins of the Qubba-i Sabz. Even Robert Byron, that went to see the ruins of this monument on the 24th of March 1934, says little about it, only one sentence:
“The Kuba-i-Sabz, which Sykes mentions, has fallen down. It was a shrine with a tall blue dome, in the Timurid style. I found its ruin incorporated in a modern house.”
“Sykes” is Sir Percy Molesworth Sykes, and Byron is referring here to Sykes’s book Ten Thousand Miles in Persia, or Eight Years in Iran, that Sykes published in 1902. This reference to an older book lets us infer that either Byron studied thoroughly the travel literature related to the area before starting his journey, or that he included this kind of remarks later when back in England he started to work to his travelogue. Either case, he studied and relied on previous sources.
Percy Sykes talks about the Qubba-i Sabz in the chapter devoted to the city of Kerman. The information that Sykes provides is not extremely accurate and is provided by the locals. In any case, from the paragraph Sykes compiled about the monument, the facts that we learn are the following.
The Qubba-i Sabz is in ruin because of an earthquake that heavily damaged the building, in 1896. Sykes also informs that the Qajar governor of Kerman, Vakil al-Mulk (governor in the 1860s), looted the monument in search of treasures, just before the earthquakes.
Before that, the Qubba was the biggest and most important building of the city of Kerman. As for the dating of the Qubba, a foundation inscription remains on the ruined walls. It was read by a local to Sykes, that translates it as follows: “The work of Ustad Khoja Shukr Ulla and Ustad Inayat Ulla, son of Ustad Nizdm-u-Din, architect of Isfahan.”. Sykes also says that the inscription contains the date of construction, that is A.H. 640 (1242-1243 c.e.).
As for the origin of the building, Sykes has doubts: on the one hand, he states the Qubba is defined as “the tomb of the Kara Khitei dynasty, and formed part of a college, known as the Madrasa of Turkabdd”, on the other hand, it possibly was part of a bigger complex ordered under the reign of the Seljuk Malik Mohamed, that Sykes calls “the seventh Seljuk sovereign”. In fact, according to Bosworth’s Islamic Dynasties, Mughith al-Din Muhammad I is the eighth Seljuk sovereign of Kerman, who ruled from 1142 to 1156.
“It is just possible that the Kuba Sabz may also have formed part of this imposing group of buildings, and this would account for its date as given in Lord Curzon’s work, 1155 A.D., but, at the same time, my informant was a well-educated man, and apparently read the inscription quite accurately; and as local information also corroborates the date he gave, it may be that the Kuba was built by Malik Mohamed and appropriated by the Kara Khitei dynasty.”
Scholars agree in defining the ruins of the Qubba-i Sabz Ilkhanid in style. The only question that remains is: if everyone that far agreed that the building dated back to the 12th century, how come that Byron defines its style as Timurid, thus dates its style to the 14th-16th century? Most probably he referred only to the decorative style, which in fact looks like later than 12th-century.
Major Percy Molesworth Sykes, Ten Thousand Miles in Persia, or Eight Years in Iran, John Murray Publisher, London, 1902, pp. 194-195. [available online (last accessed: 23rd of March 2018)]
Donald N. Wilber, The Architecture of Islamic Iran: The Il-Khanid Period, Greenwood Press, New York 1955, p. 106.