Tvrtko I of Bosnia had himself crowned king, adopting the title of "King of Serbia, Bosnia and the Coastland", in 1377.
Whether Louis had approved Tvrtko's coronation cannot be decided.
A new war broke out between Venice and Genoa in 1378.
Louis supported the Genoese and Trogir became the regular base of the Genoese fleet, which transformed Dalmatia into an important theater of war.
Louis also sent reinforcements to Francesco I da Carrara to fight against the Venetians.

The cardinals who had turned against Pope Urban VI elected a new pope, Clement VII on 20 September 1378, which gave rise to the Western Schism.
Louis acknowledged Urban VI as the legitimate pope and offered him support to fight against his opponents in Italy.
As Joanna I of Naples decided to join Clement VII's camp, Pope Urban excommunicated and dethroned her on 17 June 1380.
The pope acknowledged Charles of Durazzo, who had lived in Louis's court, as the lawful king of Naples.
After Charles of Durazzo promised that he would not claim Hungary against Louis's daughters, Louis dispatched him to invade Southern Italy at the head of a large army.
Within a year, Charles of Durazzo occupied the Kingdom of Naples, and forced Queen Joanna to surrender to him on 26 August 1381.

The envoys of Louis and Venice had meanwhile started negotiations on a new peace treaty, which was signed in Turin on 24 August 1381.
According to the treaty, Venice renounced Dalmatia and also promised to pay 7,000 golden florins as an annual tribute to Hungary.
Louis also stipulated that Venice was to transfer the relics of St Paul of Thebes to the newly established Pauline monastery at Budaszentlőrinc.

Royal charters referred to military actions in Lodomeria and Wallachia in the first half of 1382, but no further information of those wars was preserved.
Louis, whose health was quickly deteriorating, invited the representatives of the Polish prelates and lord for a meeting in Zólyom.
Upon his demand, the Poles swore loyalty to his daughter, Mary, and her fiancé, Sigismund of Luxemburg, on 25 July 1382.
Louis died in Nagyszombat in the night on 10 or 11 September 1382.
He was buried in the Székesfehérvár Cathedral in a chapel that had been built upon his orders.
Tvrtko I of Bosnia had himself crowned king, adopting the title of "King of Serbia, Bosnia and the Coastland", in 1377. Whether Louis had approved Tvrtko's coronation cannot be decided. A new war broke out between Venice and Genoa in 1378. Louis supported the Genoese and Trogir became the regular base of the Genoese fleet, which transformed Dalmatia into an important theater of war. Louis also sent reinforcements to Francesco I da Carrara to fight against the Venetians.
The cardinals who had turned against Pope Urban VI elected a new pope, Clement VII on 20 September 1378, which gave rise to the Western Schism. Louis acknowledged Urban VI as the legitimate pope and offered him support to fight against his opponents in Italy. As Joanna I of Naples decided to join Clement VII's camp, Pope Urban excommunicated and dethroned her on 17 June 1380. The pope acknowledged Charles of Durazzo, who had lived in Louis's court, as the lawful king of Naples. After Charles of Durazzo promised that he would not claim Hungary against Louis's daughters, Louis dispatched him to invade Southern Italy at the head of a large army. Within a year, Charles of Durazzo occupied the Kingdom of Naples, and forced Queen Joanna to surrender to him on 26 August 1381.
The envoys of Louis and Venice had meanwhile started negotiations on a new peace treaty, which was signed in Turin on 24 August 1381. According to the treaty, Venice renounced Dalmatia and also promised to pay 7,000 golden florins as an annual tribute to Hungary. Louis also stipulated that Venice was to transfer the relics of St Paul of Thebes to the newly established Pauline monastery at Budaszentlőrinc.
Royal charters referred to military actions in Lodomeria and Wallachia in the first half of 1382, but no further information of those wars was preserved. Louis, whose health was quickly deteriorating, invited the representatives of the Polish prelates and lord for a meeting in Zólyom. Upon his demand, the Poles swore loyalty to his daughter, Mary, and her fiancé, Sigismund of Luxemburg, on 25 July 1382. Louis died in Nagyszombat in the night on 10 or 11 September 1382. He was buried in the Székesfehérvár Cathedral in a chapel that had been built upon his orders.
Louis I of Hungary