The oldest known monarch of Arendelle was King Runeard. Succeeding him was King Agnarr, who married a member of the northern tribe Northuldra, Iduna. On the winter solstice, Iduna would give birth to Elsa, who was gifted with the ability to control ice and snow. Three years later, on the summer solstice, Iduna would have her second child, Anna, who lacked any magical abilities.
Due to the unstable nature of Elsa's powers, the castle was closed off for thirteen years, per the king's orders; this was done for Elsa's safety, as well as the safety of Arendelle's populace.
During Elsa and Anna's teenage years, Agnarr and Iduna perished in a storm at sea.
Three years after their deaths, on the day of Elsa's coronation, her magical abilities were unintentionally exposed to the public by Anna. Upon running away, Elsa accidentally sets off an eternal winter that consumes the kingdom. While Anna searched for Elsa to end the curse, Hans—a visiting prince from the Southern Isles that Anna had been engaged to—took on the task of governing the kingdom in her absence.
Unbeknown to either Anna or Elsa, Hans had hidden agendas to eventually usurp the throne to rule as king. After Elsa's incarceration as punishment for her curse, and Anna's supposed death as a result of a curse accidentally inflicted by Elsa, Hans became the illegitimate king of Arendelle, fooling the citizens into believing he and Anna married prior to her death, leaving the kingdom in his hands.
Towards the end of the film, thanks to Anna's efforts and love for her sister, Elsa found the courage to undo the eternal winter and peace was restored to the kingdom; Hans was sent back to his homeland to face punishment for his actions of treason against the princess and queen, trade was cut with the neighboring kingdom of Weselton as their duke led an assassination plot against Elsa during the eternal winter, and Elsa regained her position as reigning monarch.
Approximately three years later, the kingdom of Arendelle was at peace, filled with happy citizens who reaped the benefits of a kingdom of plenty. Elsa was a highly respected and loved ruler. The kingdom, however, was jeopardized by the elemental spirits of the Enchanted Forest, who sapped the kingdom's resources, forcing everyone to evacuate. Elsa, Anna, Olaf, Kristoff and Sven led a dangerous journey into the forest to find the source of the threat to Arendelle, while the citizens were watched over by the trolls and Grand Pabbie. The journey was ultimately successful, as they learned that the spirits were angered that the forest's magic had been drained by a dam built by their grandfather King Runeard. Anna led the Earth Giants to destroy the dam, which broke the curse, but also sent a large wave which threatened to destroy Arendelle. Elsa used her ice magic to freeze and dissipate the wave, saving Arendelle. With the curse broken, the elemental spirits' anger was sated and Arendelle was returned to its former glory. The peace between the Arendellians and the Northuldra that had been destroyed by King Runeard's actions was restored and the two cultures lived together in harmony.
The time period for Frozen is set in July 1839. In the upper left-hand corner of the geographical map shown in Frozen Fever, it is suggested by a set of Roman numerals that the year in which Anna turned nineteen was 1840. (MDCCCXL is the exact numeral order.) Oaken's statement, "A real howler in July, yes?", confirms the month is set in July. This being said, given that Anna is eighteen as of the events of Frozen, it can be logically assumed that Frozen takes place in July 1839.
The official crest of Arendelle is the crocus, appearing on various items within the kingdom such as banners, capes, flags, uniforms, wallpaper, clothing and jewelry. The colors green and purple, and to a lesser extent yellow, are associated and prominent with the kingdom of Arendelle. Crest designs usually encompass the golden yellow stylized crocus, emblazoned on a background that is purple on the left half and green on the right half. On Elsa's profile banner, the purple left half of the background is darker, and the right half is a darker yellow.
Village: The village outside the castle gates. It is comprised of homes, shops, a marketplace, the docks, and the city's clock tower.
Mountains: The vast wilderness landscape surrounding the kingdom. It is here that Arendelle's primary export—ice—is harvested. Traversing through this area can be rather dangerous, as savage wolves lurk throughout.
The name 'Arendelle' is based on the Norwegian town of Arendal, located in the county of Aust-Agder, to the southwest of the Norwegian capital, Oslo. However, the scenery of Arendelle is based primarily on Nærøyfjord in western Norway, as well as various buildings in Oslo, Bergen, and other Norwegian cities.
Arendelle's name is also similar to that of Arundel, an English market town and civil parish in a steep vale of the South Downs, West Sussex. The name was spelled 'Arundell' until 1733, when the final l was dropped. Arundel is home to Arundel Castle, seat of the Duke of Norfolk; and to Arundel Cathedral, seat of the (Catholic) Bishop of Arundel and Brighton.
In Norwegian, 'Aren' is possibly derived from 'ørn', which means "eagle", and 'delle' is derived from 'dal', which means "valley".
The crocus is a symbol of rebirth and spring. In cold regions, the flower blooms while snow is still on the ground.
The eternal winter Elsa caused may be a representation about how, in the northern reaches of Norway, winter will last anywhere from 8–10 months.
Reading further into the meaning of this kingdom's name, it's interesting to note that Walt Disney's own great-grandfather was named Arundel Disney.
In the film Big Hero 6, a ship from Arendelle can be spotted sitting in the docks.
As shown in Olaf's Frozen Adventure, several holidays belonging to a diverse selection of cultures and religions are celebrated in Arendelle.