4 surviving letters between Heraclius, correspondent of Libanius and Libanius, spanning 391 AD.
A gratitude letter praising Heraclius because his deeds outrun his promises.
A warm request that praise be restrained and Nemesius be guided back toward his city.
A second letter to Heraclius that contrasts gratitude for letters with gratitude for deeds.
A request for lawful leave so a student can see his teacher after a long absence.