Jaime II was succeeded to the Aragonese throne by Alfonso IV (1327-1336). In his brief reign, the Sasser revolt (1329) took place in Sardinia, with the support of the Genoese. The tension between the Crown of Aragon and the Republic of Genoa was very great, but it did not lead to a war. However, Alfonso IV had in his mind the project of launching a crusade against the Nasrids of Granada, in agreement, logically, with the Castilian monarch Alfonso XI. In the long run, however, that undertaking was not carried out.
Reign of Pedro IV
Pedro IV (1336-1387), known as the Ceremonious, developed throughout his long reign a spectacular work in the most varied fields . Undoubtedly, we must take into account the valuable help provided by collaborators such as Bernat Cabrera or Francesc de Perellós. One of his first steps was the incorporation of it to his domains of Mallorca , autonomous kingdom since long ago. The last exclusive monarch of Mallorca, Jaime III, was defeated in Santa Ponza (1343). A few years later he tried to recover Mallorca, but was defeated and killed by the Ceremonious troops at the battle of Llucmajor (1349). Also, Pedro IV starred in brilliant advances in the Mediterranean. The new rebellions that broke out in Sardinia led the Aragonese to fight, now yes, with the Genoese. In 1377, after the death of his son-in-law Fadrique, who had been king of Sicily, Pedro IV proclaimed himself sovereign of that island. In 1379, the duchies of Athens and Neopatria, located in the eastern Mediterranean, were added to the domains of Pedro IV. Relations with Pedro I of Castile were conflictive, degenerating into a war that lasted from 1356 to 1363. Pedro IV, in reply, decided to support the bastard Enrique de Trastámara, from whom he hoped to receive, in exchange, the coveted kingdom of Murcia. . The triumph of Trastámara did not translate into this delivery, which led to new tensions between Aragon and Castile, finally resolved in the Peace of Almazán (1375). Regarding his internal policy, the Ceremonious fought tenaciously against the Aragonese nobility, which he defeated in the battle of Épila, and against the Valencian nobility, which he defeated in Mislata, both disputes that took place in the course of the year 1348. But perhaps the most relevant event of his reign was the birth, in 1359, of the Diputación del General de Catalunya or Generalitat . That body derived from the boards that met as a result of the closure of the Catalan Courts, with the aim of controlling compliance with what was agreed upon in them. The aforementioned boards, until then of a transitory nature, became a permanent institution, which was made up of representatives of the three estates, to which were added three auditors of accounts. In any case, the last years of the reign of Pedro IV experienced some worrying symptoms, such as the financial crisis that opened in 1381.
Successors of Pedro IV
The difficulties increased in the times of Juan I (1387-1396) . In Sardinia there were new rebellions, while the distant dukedoms of Athens and Neopatria were lost. Also, the economic and social situation was more affected every day was that of the peasants of remensa, who, in the year 1388, affirmed, without a doubt in a voluntary way, that "the temps of servitude... was ja passat".
The lack of male offspring of John I made his brother Martin I (1396-1410), known as the Human, until then at the head of Sicily, succeed him on the Aragonese throne . A new rebellion in Sardinia motivated the Aragonese monarch to send his son, Martin the Younger, then King of Sicily, to fight it. Martin the Younger defeated the Sardinian-Genoese coalition in Sanluri (1409), but died shortly after, which meant the lack of heirs in the Crown of Aragon. Simultaneously, the agitation of the peasants grew and public finances continued to decline, which led to the creation in Barcelona, in the year 1401, of the Taula de Canvi, which was something similar to a municipal bank. When Martin I died, a serious succession problem arose in the Crown of Aragon.