Shaista Khan was the new Subedar of Dhaka in that time, and he did not complete the fort. In 1684, the daughter of Shaista Khan named Iran Dukht (Pari Bibi) died there. After her death, he started to think the fort as ominous, and left the structure incomplete. Among the 3 major parts of Lalbagh Fort, one is the tomb of Pari Bibi.
After Shaista Khan left Dhaka, it lost its popularity. The main cause was that the capital was replaced from Dhaka to Murshidabad. After the end of royal Mughal period, the fort became abandoned. In 1844, the area achieved its name as Lalbagh replacing Aurangabad, so the fort as Lalbagh Fort.