Which Georgian script's oldest form is Asomtavruli?

The Georgian scripts are the three writing systems used to write the Georgian language: Asomtavruli, Nuskhuri and Mkhedruli. Although the systems differ in appearance, their letters share the same names and alphabetical order and are written horizontally from left to right. Of the three scripts, Mkhedruli, once the official script of the Kingdom of Georgia and mostly used for the royal charters, is now the standard script for modern Georgian and its related Kartvelian languages, whereas Asomtavruli and Nuskhuri are used only by the Georgian Orthodox Church, in ceremonial religious texts and iconography.