He was the eldest son and heir of
Louis II of Anjou and
Yolande of Aragon.
The throne of
Aragon fell vacant in 1410 (Louis was then 6 years old) when king
Martin I of Aragon died. Louis' mother Yolande was the surviving daughter of sonless King
John I of Aragon, Martin's predecessor. They claimed the throne of
Aragon for the young Louis.
However, unclear though they were, the succession rules of Aragon and
Barcelona at that time were understood to favor all male relatives before any female (this is how Yolande's uncle, Martin of Aragon, inherited the throne of Aragon). Martin died without surviving issue in 1410, and after two years without a king, the Estates of Aragon by
Compromise of Caspe in 1412 elected Infante
Ferdinand of Castile as the next
King of Aragon. Ferdinand was the second son of
Eleanor of Aragon and
John I of Castile. The family however had secured some Aragonese lands in Montpellier and Roussillon.
Yolande and her sons regarded themselves as heirs of higher claim and began to use the title of Kings of Aragon. From this "inheritance" forward (Aragon added to other Angevin titles), Louis and Yolande were called the King and
Queen of Four Kingdoms, those four being
Sicily (including Naples),
Majorca. Of those, only the mainland part of Sicily was ever directly held by Louis, and only briefly. Louis also had claims on the title
Latin Emperor, which his grandfather
Louis I had purchased in 1383, but he never appears to have used this title.
Martin V invested Louis III on 4 December 1419 as King of Sicily (Naples). This was in contrast with the will of the childless and aged queen of the Italian kingdom,
Joanna II, who had adopted
Alfonso V of Aragon as her heir. In 1420 Louis disembarked in
Campania and besieged Naples, but had to flee at the arrive of an Aragonese fleet. Alfonso entered the city in 1421 and Louis lost the support of the Pope, tired by the costs of the war. However, when the relationships between Alfonso and queen suddenly worsened after the arrest of Joanna's lover and prime minister,
Gianni Caracciolo, the queen moved to
Aversa where Louis joined her. He was adopted and named heir in lieu of Alfonso, giving him the title of Duke of Calabria. When Alfonso had to return to Aragon, the kingdom was pacified. Louis moved to his feudal possession in
Calabria, where he lived with
Margaret of Savoy, daughter of
Amadeus VIII, Duke of Savoy. They had no children.
Louis could never become king effectively, as he died of
Cosenza in 1434. After Joanna's death the following year, his brother
René of Anjou was named King of Naples.