provenance (missals, breviaries, prayer books) appeared almost a century later. The most important purely Shtokavian vernacular text is the Vatican Croatian Prayer Book (c. 1400). Both the language used in legal texts and that used in Glagolitic literature gradually came under the influence of the vernacular, which considerably affected its phonological, morphological, and lexical systems. From the 14th and the 15th centuries, both secular and religious songs at church festivals were composed in the vernacular. Writers of early Serbo-Croatian religious poetry (začinjavci) gradually introduced the vernacular into their works. These začinjavci were the forerunners of the rich literary production of the 16th-century literature, which, depending on the area, was Chakavian-, Kajkavian-, or Shtokavian-based. The language of religious poems, translations, miracle and morality plays contributed to the popular character of medieval Serbo-Croatian literature. One of the earliest dictionaries, also in the Slavic languages as a whole, was the Bosnian–Turkish Dictionary of 1631 authored by Muhamed Hevaji Uskufi and was written in the Arebica script. Standardization In the mid-19th century, Serbian (led by self-taught writer and folklorist Vuk Stefanović Karadžić) and most Croatian writers and linguists (represented by the Illyrian movement and led by Ljudevit Gaj and Đuro Daničić), proposed the use of the most widespread dialect, Shtokavian, as the base for their common standard language. Karadžić standardised the Serbian Cyrillic alphabet, and Gaj and Daničić standardized the Croatian Latin alphabet, on the basis of vernacular speech phonemes and the principle of phonological spelling. In 1850 Serbian and Croatian writers and linguists signed the Vienna Literary Agreement, declaring their intention to create a unified standard. Thus a complex bi-variant language appeared, which the Serbs officially called "Serbo-Croatian" or "Serbian or Croatian" and the Croats "Croato-Serbian", or "Croatian or Serbian". Yet, in practice, the variants of the conceived common literary language served as different literary variants, chiefly differing in lexical inventory and stylistic devices. The common phrase describing this situation was that Serbo-Croatian or "Croatian or Serbian" was a single language. In 1861, after a long debate, the Croatian Sabor put up several proposed names to a vote of the members of the parliament; "Yugoslavian" was opted for by the majority and legislated as the official language of the Triune Kingdom. The Austrian Empire, suppressing Pan-Slavism at the time, did not confirm this decision and legally rejected the legislation, but in 1867 finally settled on "Croatian or Serbian" instead. During the Austro-Hungarian occupation