Giacomo Micaglia () (March 31, 1601 – December 1, 1654), was an Italian linguist and lexicographer, of Slavic ancestry. He was born in the town of Peschici (Apulia), at that time under the Kingdom of Naples. He said about himself to be "an Italian of Slavic language". Life Micaglia was born in Peschici, a small town on the Gargano peninsula that six centuries before (about 970) was a settlement of Croat refugees and that in those years entertained fruitful trade with Venice and the city-states on the Dalmatian coast (like the Republic of Ragusa). He was the great-uncle of Pietro Giannone (1676–1748), the historian born in Ischitella, few kilometers by Peschici. About it Giannone writes that «Scipio Giannone (his father) had married in Ischitella in 1677 Lucretia Micaglia, daughter of Matteo Micaglia from Peschici and Isabella Sabatello.» Because of his knowledge of Croatian, Micaglia was dispatched to the Republic of Ragusa by the Jesuit order. It was the time of Counter-Reformation and the Catholic Church wished to restore its power in the Balkans as well. For four years (1630–1633) he taught grammar at the Jesuit College in Ragusa (Dubrovnik). There he wrote "Latin grammar for Illyrian students" after Emanuel Alvares (De institutione grammatica pro Illyricis accommodata, 1637). A few years later, in 1636, Micaglia sent a letter to the Sacred Congregation for the Propagation of the Faith, proposing a reform of the Latin alphabet for the needs of Croatian. He discussed the same issue in the chapter "On Slavic Orthography" of his work in Croatian "God-Loving Thoughts on the Lord's Prayer Taken from the Books of St. Thomas Aquinas, the Angelic Doctor" (Bratislava, 1642). From 1637 to 1645 he was a missionary among the Catholics in Timișoara in the Banat (present day Romania). He came back to Italy, where he was confessor in Slavic languages at the Basilica della Santa Casa in Loreto, from 1645 till his death in that town. Dictionary Micaglia's greatest work is "Thesaurus of Slovinian Language and Slovinian Dictionary (where Croatian words are translated in Italian and Latin)". It was first printed in Loreto in 1649, but a better printing press was needed, so it was completed in Ancona in 1651. The dictionary was a Jesuits project, an instrument to fight the Protestant Reformation and even more the progression of the Muslim faith in the Balkans. It was the first Croatian dictionary, with Croatian (under name