Question

why were the temple destroyed in the mediaeval period

Answer 1

Mahmud of Ghazni attacked temples in the subcontinent because the temples were the seats of political power. The Brahaman priests kept all knowledge to themselves. They kept all knowledge away from the population, locked up in temples(including the knowledge to build the temple).

Answer 2

Because temples were actually the placez built by kings as a mark of pride.When other kings attacked they wanted to destroy thier pride so they destroyed templez in medieval period.