The so-called 'Blue Mosque' was once part of a complex known as the 'Muzaffariya' which included a tomb, cistern, library and khanqah. The function of the remaining building, itself in a state of ruin, has not been definitively identified.

The plan, unique in Iran, is comprised of a central square chamber covered by a dome and framed on three sides by a continuous arcade of nine domed bays. A domed sanctuary projects from the fourth, the qibla side. An entrance portal with semi-dome, on axis with the qibla, accesses the arcade, which forms a five-bay vestibule parallel with the façade. The plan bears comparison to the covered Ottoman mosques of Bursa, and Byzantine church architecture. The closest comparable structure within Iran is the Masjid-i Shah in Mashhad.

The Blue Mosque is named after, and celebrated for, its unrivaled tile decoration of which there is still evidence upon the ruined walls of the building. Both interior and exterior surfaces were once covered in a variety of tile revetment; remains of tile mosaic, under-glaze painted and over-glaze painted tiles and luster tiles attest to the richness of the decorative scheme. Patterns are rendered in subtle colors with extensive use of cobalt blue as a ground for inscriptions and arabesque designs in gold and white. The dome was a deep blue, stenciled with gold patterns.

The damage to the building is attributed to an earthquake in 1776. Extensive rebuilding took place between 1950 and 1966. The dome over the central chamber dates from this period, as do the undecorated interior walls.

Sources:

Blair, Sheila S. and Jonathan M. Bloom. The Art and Architecture of Islam. New Haven: Yale University Press, 1994.

Byron, Robert. "Timurid Architecture". In A Survey of Persian Art Vol. III, 1119-1164. Arthur Upham Pope and Phyllis Ackerman, eds. Tehran: Soroush Press, 1977.

Golombek, Lisa and Donald Wilber. The Timurid Architecture of Iran and Turan. Princeton: Princeton University Press, 1988.