Louis signed a treaty against Emperor Charles IV in Buda in February 1369. At their next meeting in Pressburg (now Bratislava in Slovakia) in September, Albert I of Bavaria, and Rupert I of the Palatinate joined their coalition against the emperor and the Habsburgs. However, Emperor Charles IV persuaded the two Wittelsbachs (Albert I and Rupert I) to break off the coalition in September 1370. Union with Poland and reforms (1370–1377) Casimir III of Poland died on 5 November 1370. Louis arrived after his uncle's funeral and ordered the erection of a splendid Gothic marble monument to the deceased king. He was crowned king of Poland in the Cracow Cathedral on 17 November. Casimir III had willed his patrimonyincluding the duchies of Sieradz, Łęczyca and Dobrzyńto his grandson, Casimir IV, Duke of Pomerania. However, the Polish prelates and lords were opposed to the disintegration of Poland and Casimir III's testament was declared void. Louis visited Gniezno and made his Polish mother, Elizabeth, regent before returning to Hungary in December. His uncle's two surviving daughters (Anna and Jadwiga) accompanied him, and the Polish Crown Jewels were transferred to Buda, which raised discontent among Louis's new subjects. Louis's wife gave birth to a daughter, Catherine, in 1370, seventeen years after their marriage; a second daughter, Mary, was born in 1371. Thereafter Louis's made several attempts to safeguard his daughters' right to succeed him. During a war between Emperor Charles IV and Stephen II, Duke of Bavaria, Louis intervened on the duke's behalf and the Hungarian army invaded Moravia. After the duke and the emperor signed a peace treaty, Louis and the emperor agreed upon the betrothal of their children early the next year. The Ottomans annihilated the Serbian armies in the Battle of Marica on 26 September 1371. Lazar Hrebeljanović, one of the Serbian lords, swore loyalty to Louis. Pope Gregory XI urged Louis to resist the Ottomans but also pleaded with him to send reinforcements to Italy to fight against Bernabò Visconti. A war broke out between the Republic of Venice and Francesco I da Carrara, Lord of Padova, who was an ally of Louis, in the summer of 1372. Louis sent reinforcements to Italy to assist Francesco da Carrara. The Venetians defeated the Hungarian troops at Treviso and captured its commander, Nicholas Lackfi, forcing Louis I to sign a peace treaty on 23 September 1373. Louis and the representatives of