Change of capital city Colombo to Kotte in Sri Lanka?

It is in Sri Jayawadanepura Kotte now. The change came in the 70s when the parliament was moved there. Colombo remains as the commercial capital being the largest city and main port. Kotte was also a capital in the 1400s before Kandy (1500s) and Colombo (1800s) so it is fair to say that it was reinstated as capital. I don't know a definite reason but the president who changed it was named J. R. Jayawardane.