The term "tercio" was first used with Spanish garrisons in Italy under the Holy Roman Emperor Charles V. In his ordinances of 23 October 1534 and 15 November 1536 (Genoa ordinance), Charles organized his army in three Tercios, one in the Kingdom of Sicily, another in the Duchy of Milan (Kingdom of Lombardy), the last in the Kingdom of Naples. These units became known as the "Tercios Viejos" (Old Tercios): the Tercio of Sicily ("Tercio Viejo de Sicilia"), Tercio of Naples ("Tercio Viejo de Nápoles") and the Tercio of Lombardy ("Tercio Viejo de Lombardía"). Shortly after came the Tercio of Sardinia ("Tercio Viejo de Cerdeña ") and the Tercio of the Galleys ("Tercio de Galeras"), the first marine infantry unit in history. Subsequent units would be known as "New Tercios".