On the southern side, the great ravine would make a continuous wall difficult to build, and, had one existed, we should expect to find the upper part of this ravine filled up, which Is not the case. So we may consider FIrozabad to have been a collection of suburbs, with no con- taining wall, Firoze Shah having only concerned himself to build a wall round his Kotlla and round his hunting-park. Had there been the materials for a wall, It Is not likely that Sher Shah would have despoiled SIri and Jahanpanah of their walls. In order to surround his city and raise the walls of the Purana Klla. Again, It does not seem to have been a matter of difficulty to occupy FIrozabad ; fighting frequently took place In the streets ; kings, when they were threatened, preferred to shut themselves up in SIri ; when TImur came, it was the old cities of SIri, Jahanpanah, and Delhi which were held against him. All this goes to show that FIrozabad was not a walled city.
If we accept the fact that FIrozabad had no city walls, we can quite understand why Sher Shah should wish to build defensive walls. He chose that portion of FIrozabad which lay contiguous to the Purana Kila ; but how much of his walls he was able to complete is very doubt- ful, for his reign was a short one. His son
