Old Church Slavonic in Romania
Old Church Slavonic was the main language used for liturgical and administrative purposes by the Romanians until the 18th century, being still used in the Orthodox Church until mid-19th century.
The language, while based on Old Church Slavonic, was influenced by the Slavic languages used by surrounding peoples. The most important influences were from Middle and Modern Bulgarian, with some smaller influences from Serbian (in Wallachia) and Russian (in Moldavia). Starting with the 15th century, the language was also influenced by Romanian.
After the Slavic migrations, Slavonic became the liturgical language of the Eastern Orthodox Church in present-day Romania, under the influence of the South Slavic feudal states. The exact timing of this change happened is not known, but it was probably in the 10th century. While the language was not understood by most Romanians, it was a language known by the bishops, the monks, some of the priests, the clerks, the merchants, the boyars and the Prince.
Old Church Slavonic was also used as a literary language, for example in chronicles, story-books, law codexes (known as pravila), property documents (hrisov), decrees of the voivodes or boyars, diplomatic correspondence and sometimes even in private letters. It also led to an integration of the written Romanian culture into the Slavic culture of the neighbours.
Replacement with Romanian 
The earliest contracts (zapis) to be written in Romanian rather than Slavonic date from 1575-1590 and by 1655-1660, all the administrative documents at the Princely Courts of both Wallachia and Moldavia were written in Romanian.
The replacement of Slavonic religious texts with Romanian versions began with the first translations in Maramureş in late 15th century, further translations being created in Transylvania after the Protestant Reformation. In Wallachia, the gospels were translated into the vernacular between 1512-1518 and by the middle of the 16th century, the earliest religious works were printed, while the first complete bible in Romanian being print in Bucharest in 1688.
Legacy and assessments 
Coresi, the printer of the first Romanian-language book, saw in 1564 no good in the usage of Old Church Slavonic as a liturgical language, as the priests speak to the people in a foreign language, arguing that all the other peoples have the word of God in their language, except for the Romanians. Dimitrie Cantemir, a Moldavian scholar who published the first novel in Romanian, saw the usage of Old Church Slavonic as a "barbarism", which caused a cultural regression.
However, there were some cultural accomplishments done in the Old Church Slavonic language, such as a number of chronicles and historiographical works in Moldavia or Neagoe Basarab's Teachings to his son Theodosie.
See also 
- Costăchel et al., p.504-505
- Georgescu, p.66
- Costăchel et al., p.505-506; 513
- Costăchel et al., p.505
- Costăchel et al., p.513
- Costăchel et al., p.511
- Georgescu, p.67
- V. Costăchel, PP Panaitescu, A. Cazacu. (1957) Viaţa feudală în Ţara Românească şi Moldova (secolele XIV–XVI) ("Feudal life in the Romanian and Moldovan Land (14th–16th centuries)", Bucureşti, Editura Ştiinţifică
- Vlad Georgescu. (1991) The Romanians: a history, Ohio State University Press. ISBN 0-8142-0511-9