In 1376-77, Ibrahim Naib Barbak under Firuz Shah Tughluq of Delhi (1351-1388) built the first citadel in Jaunpur where the Sharqi kings resided. In style, it is kin to the Tughluqid architecture of Delhi. A mosque was also built at the same time; it consists of a long rectangular prayer hall entered from a triple archway at center. There is a free standing commemorative column in front of the mosque.
Sources:
Williams, John A. and Caroline. 1980. Architecture of Muslim India. Set 4, The Sultanate of Jaunpur About 1360-1480. Santa Barbara, California, Visual Education Inc.