It is evident from what has been said, that before 500 A.D. literary chronology, even in the Sanskrit period, is almost entirely relative, priority or posteriority being determined by such criteria as development of style or thought, the mention of earlier authors by name, stray political references as to the Greeks or to some well-known dynasty, and allusions to astronomical facts which cannot have been known before a certain epoch. Recent research, owing to increased specialisation, has made considerable progress towards greater chronological definiteness. More light will doubtless in course of time come from the political history of early India, which is being reconstructed, with great industry and ability, by various distinguished scholars from the evidence of coins, copper-plate grants, and rock or pillar inscriptions. These have been or are being published in the Corpus Inscriptionum Indicarum, the Epigraphia Indica, and various journals devoted to the study of Indian antiquities. The rise in the study of epigraphy during the last twenty years has, indeed, already yielded some direct information of importance about the literary and religious history of India, by fixing the date of some of the later poets as well as by throwing light on religious systems and whole classes of literature. Thus some metrical inscriptions of considerable length have been deciphered, which prove the existence of court poetry in Sanskrit and vernacular dialects from the first century of our era onwards. No direct evidence of this fact had previously been known. The older inscriptions are also important in connection with Sanskrit literature as illustrating both the early history of Indian writing and the state of the language at the time. The oldest of them are the rock and pillar inscriptions, dating from the middle of the third century B.C., of the great Buddhist king Açoka, who ruled over Northern India from 259 to 222 B.C., and during whose reign was held the third Buddhist council, at which the canon of the Buddhist scriptures was probably fixed. The importance of these inscriptions can hardly be over-rated for the value of the information to be derived from them about the political, religious, and linguistic conditions of the age. Found scattered all over India, from Girnar (Giri-nagara) in Kathiawar to Dhauli in Orissa, from Kapur-di-Giri, north of the Kabul river, to Khalsi, they have been reproduced, deciphered, and translated. One of them, engraved on a pillar erected by Açoka to commemorate the actual birthplace of Buddha, was discovered only at the close of 1896.