On 5 December 1835 readers of Croatia’s first national newspaper, Novine Horvatske [The Croatian News], might have found themselves rubbing their eyes in disbelief as they surveyed the daily editorial. From the new year, they were told, the paper would be changing its name to one ‘common to all South Slavs,’ the Illyrian People’s News [Ilirske narodne novine]. But if, as they stared down at the page, it felt like their brains were taking a little longer to process the information than normal, it was not last night’s wine that was to blame. For along with its new name, the paper would henceforth be written in a new language as well. Kajkavian, the dialect common to the land around Zagreb, the capital, was out; in its place came Shtokavian, versions of which were spoken throughout the Balkan Peninsula.

The author of the editorial was a certain Ljudevit Gaj, a precocious 26-year-old who had already gained a considerable reputation as the first person to create a standardised Latin script for writing in Serbo-Croat. Born in Krapina, a town in northern Croatian, in 1809, Gaj’s early career took him first to Vienna, and then on to Budapest, the two principal cities of the recently established Austrian Empire. By the time he was 17, Gaj had published his first work, a treatise on manor houses in his local district, and within a few years the Concise Basis for a Croatian-Slavonic Orthography (1830) had appeared, laying the groundwork for his future endeavours.

Despite the outwardly peaceful conditions that had prevailed in Europe since the end of the Napoleonic Wars, beneath the surface there were still tensions. Nowhere was this more apparent than in the archly conservative Austrian Empire, the great bulwark at the heart of Europe, where the two largest elements of the Habsburg dominions — the Austrian Crownlands and the Kingdom of Hungary — found themselves in opposition. Although the latter had for several hundred years accepted the Austrians as their overlords while retaining a degree of autonomy, a series of reforms by the Emperor Joseph II had begun to aggravate long-held divisions. Most notable of these was an attempt to switch the official language of the empire from Latin to German, a move perceived by Hungary’s nobility as a threat to their cultural heritage.

Before long, the Hungarian campaign to preserve the use of their own language became an expansive push towards the ‘Magyarisation’ of the other lands of the Kingdom of Hungary — including Gaj’s Croatia. It is in the context of the growing pressure of Hungarian nationalism that the genuinely revolutionary nature of Gaj’s orthographic project is revealed. His codified Serbo-Croat, which emerged just as the Hungarian national movement was gathering steam, laid the groundwork for the project that would cement Gaj’s status in the Croat imagination: the Illyrian movement.

This campaign was strikingly different to other ethnic nationalist movements of the era. For Gaj, the Croats were just one constituent part of a larger whole, sprung from what he labelled ‘the Slavic spirit,’ alongside the Serbs, Slovenes, Bosnians, Montenegrins and other ethnic peoples of the region. In the same way that in classical antiquity the term ‘Illyrian’ came to refer to a number of different tribes living in the area we today call the Balkans, Gaj saw the South Slavs of the Austrian Empire as a collective. He shared the same vision as Janko Draskovic, scion of one of the most distinguished Croat families, who in 1832 had submitted a treatise to the Hungarian Diet calling for the formation of a semi-autonomous Greater Illyria, subject not to Hungary but to the Austrian emperor himself. For Draskovic, the refusal of these terms could only mean one thing: the secession of the united Croatian lands.

In his 1835 proclamation, Gaj reached for a musical metaphor to illustrate his supranational vision. Illyria, he told his readers, is the ‘lyre of Europe,’ and its different peoples are its strings. Through his unifying push, the lyre will be reassembled ‘into a single harmony’ drowning out the ‘foreign tunes’ that threaten Slavic identity. But to do this, he goes on to say, a single common language is required, one that ‘is not found in a single place, or a single country, but in the whole of Illyria’ – Shtokavian. From now on, the Illyrian People’s News, alongside the Illyrian Morning Star, would speak to this newly-fashioned community in their own voice.

There were two reasons why Gaj chose Shtokavian as the dialect of choice for his new movement. First and foremost, it was the most widely spoken of the Croat tongues, with a far wider reach than Kajkavian. But it also had a deeper significance for his programme. Just as in his choice of the newspaper’s name, Gaj was harking back to the classical past, and the selection of Shtovakian was calculated to tap into the legacy of one of the great civilisations of the Adriatic seaboard, the Republic of Ragusa, only recently been annexed to the Kingdom of Italy by Napoleon.

Ragusa — modern Dubrovnik — was an aristocratic trading state of a similar type to Venice, its rival across the water. Under its somewhat ironic motto ‘Non bene pro toto libertas venditur auro’ — ‘liberty is not sold for all the gold in the world’ (in reality, the state had paid an annual tribute to the Ottoman Empire for centuries) the Ragusans had done commercial battle with the great powers of the day, taking advantage of their preferential status in Constantinople and the access to the Black Sea it granted.

But besides their commercial and diplomatic nous, the great Ragusan gift to Gaj and his fellow Illyrians was a rich tradition of Renaissance and Baroque literature, written in Shtokavian. Much of this work, especially that of the poet Ivo Gundulic, addressed the notion of liberation from the Ottoman yoke, delivered through the great Slavic brotherhood. For Gundulic, as the writer Marcus Tanner has pointed out, that liberator would be the Poles, to whom he dedicated his epic poem Osman, after their defeat of the Ottomans at the Battle of Hotin in 1621.

Thus, the choice of Shtokavian gave to Gaj’s nascent movement the authority of history. The struggle was no longer against the Ottomans, but the Austrians and Hungarians, whose rule could only be challenged by a single, united Slavic group. Although it began as an explicitly cultural movement focused on the propagation of a common identity through literature, before long the Illyrian movement had evolved into a political party proper, taking its place in the Croat parliament — the Sabor — in 1843.

By the end of that decade, however, the idea of Illyria was dead — for the time being at least. After the revolutions of 1848, the new Austrian emperor, Franz Joseph, reasserted the Habsburg grip upon its possessions, cracking down on the Empire’s various secessionist movements. But as with many of Europe’s national movements, once the genie was out of the bottle, it could never be fully put away again. So it was in 1919, less than a half-century after Gaj’s death in 1872, that the Kingdom of Serbs, Croats, and Slovenes — Yugoslavia — was born, the full realisation of Gaj’s vision of Slavic unity that would persist until the tragedy of the Balkan Wars of the 1990s.