A Pallippadai is a temple constructed in memory of the desceased probably on top of the burial ground or on top of the cremated ash pot (this is not clear to me as of now). It will be hard to distinguish a pallipadai temple from a normal temple in terms of the overall structure. Almost all members of a normal temple structure are present in pallipadais too. were meant only for the royal classes and not for common people. This raises several questions. * Were common people incapable of constructing a temple for their loved ones? Not really. We have inscriptional evidence showing army chiefs and other contributing for other temples, constructing vimanas etc.
* Was there any religious reason behind this ? We do not know. Kudanthai sethuraman had postulated that pallipadais were constructed on top of those royal people who were given siva deeksha. But it is quite a common fact that anybody with a pious mind and maturity may be given deeksha by a suitable guru when he finds a suitable desciple.
Whatever may be the reason, both inscriptional evidence and material evidence attest the fact that only royal classes had pallipadais.
The earliest of pallipadais starts occuring during the last days of pallava monarchy. We find ganga king prithivipathi being honoured with pallipadai. This is followed by the famous Kothanda rameeswaram - a pallipadai apparently built for Aditya I near kalahasthi. On a side note, kalahasthi seems to have been adored as an important place from Aditya's times all the way to Rajendra. Possibly some kind of matrimonial relationship with the chieftians of the area ? I'm not sure.
The Kothanda rameeswaram inscriptions mentions one Vageesa panditha padaarar - postulated to be the guru of Aditya I.