Giacomo da Lentini, also gave birth to the Sicilian School, widely inspired by troubadour literature. It is in this language that appeared the first sonnet, whose invention is attributed to Giacomo da Lentini himself. Sicilian was also the official language of the Kingdom of Sicily from 1300 to 1543. Prior to the 20th century, large numbers of Sicilian people spoke only Sicilian as their mother tongue, with little or no fluent knowledge of Italian. Today, while Sicilian is an unrecognized language being used as part of many people's daily life, Italian is the only official language and predominates in the public arena. The Siculo-Arabic dialect was a vernacular variety of Arabic once spoken in Sicily and neighbouring Malta between the end of the ninth century to the mid to late thirteenth century. The language became extinct in Sicily, but in Malta it eventually evolved into what is now the Maltese language. The Siculish dialect is the macaronic "Sicilianization" of English language words and phrases by immigrants from Sicily to the United States in the early 20th century. Forms of Siculish are also to be found in other Sicilian immigrant communities of English-speaking countries, namely Canada and Australia. A surprising similarity can often be found between these forms, through either coincidence, trans-national movements of Sicilian immigrants, or more likely, through the logical adaptation of English using linguistic norms from the Sicilian language. Ethno-linguistic minorities There are two main historical ethno-linguistic minorities in Sicily, the Lombards of Sicily and the Arbëreshë: The Lombards of Sicily are a linguistic minority living in Sicily who speak an isolated variety of Gallo-Italic dialects, the so-called Gallo-Italic of Sicily. The Gallo-Italic of Sicily is a group of Gallo-Italic languages found in about 15 isolated communities of central eastern Sicily. Forming a language island in the Sicilian language, it dates back to migrations from Northern Italy during the era of Roger I of Sicily and his successors. The Lombards of Sicily, who originally hailed from Northern Italy, settled the central and eastern part of Sicily about 900 years ago, during the Norman conquest of Sicily. Because of linguistic differences among the Gallo-Italic dialects of Sicily, it is supposed that there were different immigration routes. From Piedmont, Liguria, Emilia, and Lombardy they began to spread south between the 11th and 14th centuries. The most important areas where the Gallo-Italic of Sicily is spoken are Acquedolci, Montalbano Elicona, Novara