Griffith Jones was rector of Llanddowror in Carmarthenshire. From 1731 he organised circulating schools: teachers stayed in a parish for about three months, usually in winter when farm work was light, teaching children and adults to read the Welsh Bible.
By his death in 1761 thousands of schools had been held and a large part of the population had learned to read. Catherine the Great of Russia had a report made on the scheme.
Rheithor Llanddowror yn Sir Gaerfyrddin oedd Griffith Jones. O 1731 trefnodd ysgolion cylchynol: byddai athrawon yn aros mewn plwyf am tua thri mis, fel arfer yn y gaeaf pan oedd gwaith fferm yn ysgafn, gan ddysgu plant ac oedolion i ddarllen y Beibl Cymraeg.
Erbyn ei farwolaeth yn 1761 roedd miloedd o ysgolion wedi’u cynnal a rhan fawr o’r boblogaeth wedi dysgu darllen.