The Principality of Achaea had passed out of the native Villehardouin line and into Angevin hands through the Treaty of Viterbo, following the death of William II Villehardouin in 1278. The Angevins of the Kingdom of Naples treated Achaea as a possession to be managed, leased, and married off. They had granted it to William's elder daughter Isabella of Villehardouin, then reclaimed it in 1307 after her husband Philip of Savoy mismanaged it. When Isabella died in 1312, her younger sister Margaret claimed the principality under her father's will — a claim that conflicted directly with the Treaty of Viterbo. The Angevins, in response, arranged the marriage of Isabella's eldest daughter Matilda of Hainaut to Louis of Burgundy in 1313 and invested the couple with the principality. Margaret arranged the competing marriage of her daughter Isabella of Sabran to Ferdinand of Majorca, a prince of the House of Barcelona and no friend of the Angevins. The principality now had two rival rulers, each backed by a different royal house, each claiming legitimacy through a different branch of the same defunct ruling family.

Ferdinand arrived first, in mid-1315, landing near the port city of Glarentza on the western Peloponnesian coast. After an initial setback he took the port, then swept east and south across the plain of Elis, including Andravida, the principality's capital, completing his conquest by 17 August 1315. Louis was still in Venice, raising funds. While Louis delayed, his wife Matilda travelled directly to the principality, where several local lords — including John I Orsini, the count of Cephalonia, and Nicholas of Dramelay, the baron of Chalandritsa — abandoned their earlier oaths to Ferdinand and declared for her. Ferdinand attacked and took Chalandritsa in response, but could not take Patras. Louis eventually arrived, failed in his own attack on Chalandritsa, and then moved to Patras, where Byzantine forces from Michael Kantakouzenos, governor of Mistra, reinforced his army. Ferdinand was expecting help of his own: troops from the Catalan Company, then occupying the Duchy of Athens, were on their way. Rather than fall back to Glarentza to await them, he chose to give battle.

On 5 July 1316, the two forces met on the plains near Manolada. At the outset, the Majorcan troops broke through the first Burgundian line — the one commanded by John Orsini, count of Cephalonia. It looked, for a moment, as though Ferdinand's gamble might pay off. But the second line, under Louis's direct command, crushed the Majorcan charge. In the confusion, Ferdinand was knocked from his horse. Before anyone could restrain the situation, he was killed — inadvertently slain, the sources say, before he could be taken prisoner and ransomed. His death broke the Majorcan formation. Many of his troops fled toward Glarentza. John II of Nivelet, who had changed sides to Ferdinand, was executed on the field by Louis as a traitor. The next morning, Ferdinand's head was displayed at the gates of Glarentza, still held by his garrison. The Catalan reinforcements, having reached as far as Vostitsa by the time of the battle, turned around and went back to Athens on news of Ferdinand's death. Troops from Majorca arrived by sea ten days later and proposed holding Glarentza for Ferdinand's son James; eventually, after bribes, they surrendered the city to Louis.

Louis of Burgundy did not long enjoy what he had won. Four weeks after the battle, he was dead — cause unrecorded, but the medieval Peloponnese in summer offered several plausible candidates. He left behind his wife, Matilda of Hainaut, twenty-two years old and twice widowed, ruling a principality the chroniclers were already calling crumbling. The Catalan Company was still in Athens, still a threat along the frontier. The local lords whose loyalty had shifted once might shift again. The short-term effect of Manolada was clear: the Angevin line held, the rival claim of the Villehardouin sisters was suppressed, the Catalans were checked. But it was a victory won at tremendous personal cost to both claimants. Ferdinand left a young son; Louis left a young widow. The plain of Elis settled back into its ordinary rhythms, and the principality stumbled on.

Historians have noted that the Battle of Manolada had consequences reaching beyond the Peloponnese. Had Ferdinand prevailed, the House of Aragon — through its Catalan allies — stood to acquire not only Achaea but potentially Athens as well, uniting much of southern Greece under a single Aragonese-Catalan umbrella. Ferdinand's death effectively ended that possibility. His son James eventually pursued the family's claims through other means, but the long minority that followed and the turbulent career James led could not recapture what a living Ferdinand might have built. The marsh plains of Elis, quiet and flat, were an unlikely arena for the reshaping of southeastern European politics. But that is what they became, briefly, on a July morning in 1316.