Samuil Micu Klein (September 1745 – 13 May 1806) was a Romanian Greek-Catholic theologian, historian, philologist and philosopher, a member of the Enlightenment-era movement of Transylvanian School (Şcoala Ardeleană).
[1] Born as Maniu Micu in the Transylvanian village of Sadu, in the Principality of Transylvania (now in Sibiu County, Romania), he was the son of a Greek-Catholic protopope and the nephew of bishop Inocenţiu Micu-Klein.
[2] In 1772, returning to Blaj to teach ethics and mathematics at the Seminary, Klein met and befriended bishop Grigorie Maior, whom he accompanied in visits throughout his diocese, trying to win converts to Greek-Catholicism.
[4] He went to Vienna in 1779 to become a prefect of studies at the Saint Barbara College, he published in 1780, together with Gheorghe Sincai the first Romanian grammar, Elementa linguae daco-romanae sive valachicae.
[4] Klein returned to Blaj, and between 1782 and 1804, he was very productive both in his translations and in writing original works:[5] and Cartea de rugăciuni (‘Book of Prayers’, printed at Vienna in 1779) in which he used for the first time the etymological alphabet.