County of Forcalquier in the context of "Louis I of Naples"

Charles I (Italian: Carlo; early 1226/1227 – 7 January 1285), commonly called Charles of Anjou or Charles d'Anjou, was King of Sicily from 1266 to 1285. He was a member of the Capetian dynasty and the founder of the House of Anjou-Sicily. Between 1246 and 1285, he was Count of Provence and Forcalquier in the Holy Roman Empire and Count of Anjou and Maine in France. In 1272 he was proclaimed King of Albania, in 1277 he purchased a claim to the Kingdom of Jerusalem, and in 1278 he became Prince of Achaea after the previous ruler, William of Villehardouin, died without heirs.

The youngest son of Louis VIII of France and Blanche of Castile, Charles was destined for a church career until the early 1240s. He acquired Provence and Forcalquier through his marriage to Beatrice. His attempts to restore central authority brought him into conflict with his mother-in-law, Beatrice of Savoy, and the nobility. He relinquished control of Forcalquier to his mother-in-law in 1248, although she returned it to him in 1256. Charles received Anjou and Maine from his brother, Louis IX of France, in appanage. He accompanied Louis during the Seventh Crusade to Egypt. Shortly after he returned to Provence in 1250, Charles forced three wealthy autonomous cities—Marseille, Arles and Avignon—to acknowledge his suzerainty.

The Capetian House of Anjou, or House of Anjou-Sicily was a royal house and cadet branch of the Capetian dynasty. It is one of three separate royal houses referred to as Angevin, meaning "from Anjou" in France. Founded by Charles I of Anjou, the youngest son of Louis VIII of France, the Capetian king first ruled the Kingdom of Sicily during the 13th century. The War of the Sicilian Vespers later forced him out of the island of Sicily, leaving him with the southern half of the Italian Peninsula, known as the Kingdom of Naples. The house and its various branches would go on to influence much of the history of Southern and Central Europe during the Middle Ages until it became extinct in 1435.

Historically, the house ruled the Counties of Anjou, Maine, Touraine, Provence and Forcalquier; the Principalities of Achaea and Taranto; and the Kingdoms of Sicily, Naples, Hungary, Croatia, Albania and Poland.

The land of Provence has a history quite separate from that of any of the larger nations of Europe. Its independent existence has its origins in the frontier nature of the dukedom in Merovingian Gaul. In this position, influenced and affected by several different cultures on different sides, the Provençals maintained a unity which was reinforced when the region was made a separate kingdom during the Carolingian decline of the later ninth century. When Boso of Provence acquired the region in 879, it was known as Lower Burgundy until it was merged with Upper Burgundy in 933 to form the Kingdom of Arles. The counts of Arles began calling themselves "count of Provence"; although in name vassals, they were de facto autonomous princes. After 1032, the county was part of the Holy Roman Empire.

In the eleventh century, Provence became disputed between the traditional line and the counts of Toulouse, who claimed the title of "Margrave of Provence". In the High Middle Ages, the title of Count of Provence belonged to local families of Frankish origin, from 1112 to 1245 to the House of Barcelona (a cadet branch of the House of Aragón), from 1245 to 1382 to the House of Anjou, and from 1382 to 1481 to a cadet branch of the House of Valois. It was inherited by King Louis XI of France in 1481, and definitively incorporated into the French royal domain by his son Charles VIII in 1487.

Joanna I, also known as Johanna I (Italian: Giovanna I; December 1325 – 27 July 1382), was Queen of Naples, and Countess of Provence and Forcalquier from 1343 to 1381; she was also Princess of Achaea from 1373 to 1381.

Joanna was the eldest daughter of Charles, Duke of Calabria and Marie of Valois to survive infancy. Her father was the son of Robert the Wise, King of Naples, but he died before his father in 1328. Three years later, King Robert appointed Joanna as his heir and ordered his vassals to swear fealty to her. To strengthen Joanna's position, he concluded an agreement with his nephew, King Charles I of Hungary, about the marriage of Charles's younger son, Andrew, and Joanna. Charles I also wanted to secure his uncle's inheritance to Andrew, but King Robert named Joanna as his sole heir on his deathbed in 1343. He also appointed a regency council to govern his realms until Joanna's 21st birthday, but the regents could not actually take control of state administration after the King's death.

The County of Provence was a largely autonomous medieval state that eventually became incorporated into the Kingdom of France in 1481. For four centuries Provence was ruled by a series of counts that were vassals of the Carolingian Empire, Burgundy and finally the Holy Roman Empire, but in practice they were largely independent.

Beatrice of Provence (c. 1229 – 23 September 1267), was the ruling Countess of Provence and Forcalquier from 1245 until her death, as well as Countess of Anjou and Maine and Queen of Sicily by marriage to Charles I of Naples.

Beatrice was the fourth and youngest daughter of Ramon Berenguer V, Count of Provence and Beatrice, daughter of Count Thomas I of Savoy and Margaret of Geneva.