The South Slavic language of Croatian is most commonly spoken by Croats in Croatia and in Bosnia and Herzegovina. The current form of the language is a mixture of Croatian Church Slavonic and the vernacular language which has been evolving for nearly a millennium. In terms of the history of the language, its development has been somewhat complicated, with a few notable events which have affected the language as we know it today.
Written Croatian documents can be traced back as far as the 9th century, mainly by looking at religious texts. This is because Old Church Slavonic (as it was then known) was the language of the liturgy at that time. The influence of religion, not just in Croatia but worldwide, was such that the language gradually gained momentum and began to be used for non-liturgical purposes. It was around this time that the language took on a specifically Croatian identity as opposed to a general Slavonic nature. This Croatian Old Slavonic continued to be used until the 16th century, and was employed alongside Latin and ‘Croatian’ as it was then known. Slowly, texts written solely in Croatian began to appear and began to be accepted, and it could have been partly due to the recognition of Croatian Old Slavonic that pure Croatian started to take off. During the 14th and 15th centuries the modern Croatian language emerged, although the Old Slavonic remained in its position of prominence until the 16th century. The Croatian of the 14th and 15th centuries only differs slightly from the standard language today.
Two domestic prince dynasties ruled semi-autonomous Croatia at the time of the 17th century. They attempted unification on both cultural and linguistic levels and selected an official language for the country. They chose a transitional dialect in a decision thought by many to be very wise, as it was a rare mixture of all the main contemporary Croatian dialects. The variant is still used now in the north, as well as in some parts of central Croatia. Almost inevitably, it was this form of the language which went on to become the language of administration and any important documents were recorded in this official tongue. It would seem that the Croatian language blossomed in harmony, and to a point this might be true, but both dynasties were executed in 1671, and at this point Austrian influences affected the way in which the Croatian language grew. It took four more centuries for the Croatian language to settle, due to the unusual complications incurred by its being a three dialect and three script tongue. What this means is that there are three ways to write and three ways to say everything.
The nuances in the language developed in an extremely complicated manner, but the area which really needs further exploration is the link Croatia has with Serbia and how this has affected the Croatian language. The two languages had been joined together for bureaucratic reasons during the 19th century, and the idea was born to create a Serbo-Croatian language. This meant many grammatical and orthographical reforms for Croats, with the main influences coming from South Slavic dialects. Joint languages have been a sought after ideal for countries such as Serbia, Montenegro and Croatia for many years, and the creation of hybrids often reflect the political trauma or upset of the time. For example, when Yugoslavia existed, a new joint language was attempted which bowed to Yugoslav ideology. Serbian and Croatian were forced to merge, but because there were far more Serbs than Croats, the language was heavily influenced by Serbian rather than Croatian. These linguistic ideals continued in one form or another for the best part of the 20th century and inevitably influenced the purity of the Croatian language. Linguists and writers of course were strongly opposed to the attempts to merge languages, as were many people with strong senses of national identity, as language is intrinsically linked to the essence of a country. The suppression of the Croatian language continued however and was used as a political tool in order to suppress the Croats themselves. For example, again during the Communist era the Serbian influence over the language again gained strength.
Declarations and agreements were always made which promised that Slavic languages were equal, but they simply failed to make any difference in the real world. This continued until the 1950’s when the “Novi Sad Agreement” was made, in a Serbo-Croatian orthography. Far from calming the public, it enraged them, prompting unrest which lasted until action was taken in 1967 when a collective Croatian reaction against such Serbian imposition erupted when nineteen Croatian scholarly institutions and cultural organizations dealing with language and literature (Croatian Universities and Academies), including foremost Croatian writers and linguists issued the "Declaration Concerning the Name and the Status of the Croatian Literary Language". In the Declaration, they asked for amendment to the Constitution recognising equality between Slovenian, Croatian, Serbian and Macedonian, along with the use of Croatian in schools and in the media. The declaration essentially ended the forced Serbo-Croatian unification which had existed for so long.