From thence he advanced to Ujjain-Nagari and destroyed the idol-temple of Mahakal Diw. The effigy of Bikramjit who was sovereign of Ujjain-Nagari, an… - Iltutmish

The tomb of Shamsu'd-Din Iltumish... was built in about 1235 by Iltumish himself, only five years after the construction of Sultan Ghari's tomb. Yet it is quite different from the latter and illustrates that phase in the develpment of Indo-Islamic architecture when the builder had ceased to depend for material on the demolition of temples, although the arches and semi-domes below the squinches were still laid in the indigenous corbelled fashion. ... The tomb is plain on the outside, but is profusely carved on the entrances and in the interior with inscriptions in Kufi and Naskh characters and geometrical and arabesque patterns in Saracenic tradition, although several motifs among its carvings are reminiscent of Hindu decoration. ... In view of its lavish ornamentation, Fergusson described it as 'one of the richest examples of Hindu art applied to Muhammadan purposes.' [...] The monument [Sultan Ghari] exemplifies the same phase in tomb-architecture, as we find in the Quwwatu'lIslam mosque: it is built with architrectural members removed from temples and employs the trabeated construction with which the indigenous architects were familiar.

That the practice of utilizing the spoils of Hindu temples continued throughout the reign of Sultan Iletmish is proved by the Mosque of Ukha in Bayana (Uttar Pradesh), which is also on the site of a Hindu temple…

Next, Sultan Iltutmish (r. 1210–36) spent his early years in suppressing the Turkish opponents. He was also in fear of invasion by Genghis Khan. In 1226, he attacked Ranthambhor. Minhaj Siraj records that ‘much plunder fell into the hands of his followers;’dccvii the plunder obviously included slaves. In the 1234–35 attack of Ujjain, he made captives of the ‘women and children of the recalcitrant,’ according to Shiraj and Ferishtah.