Archaeologist Nagaswamy has this to say of Mahendramangalam and the temple:
Mahendramangalam on the northern bank of the River Cauvery was established as a Brahmin settlement by the Pallava ruler, Mahendravarman (590-630) whose records are found in the upper Tiruchi rock cut cave.
The village was in a flourishing condition in the 10th century, evidenced by the fragmentary record. Obviously, a temple for Siva had come up then and judging from the dimension of the surviving base, it should have been a temple of impressive size.
The fragmentary inscription in Tamil, in 10th century Tamil script refers to a gift to certain God – ‘Tillai Nathan', probably the presiding deity of this temple to which this stone belongs. The stone is similar to the one found in the nearby temple at Srinivasanallur, well known for its Chola temple and sculptures. There is an inscription of Rajakesari identified with Aditya Chola, assignable to 900 A.D. This refers to Mahendramangalattu Sabhayar (assembly).
Mahendramangalam figures as a battlefield in the 13th century, in the war between Sundara Pandyan, Hoysala Narasimha and Rajaraja III. This reference is found in a Sanskrit text. The fragmentary inscription is interestingly in Tamil verse, not in the prose form.