The Royal Palace of Alderaan, also known as House Organa, was a refined structure with centuries of history, situated in the heart of Aldera, the capital city of the planet Alderaan. During the decline of the Galactic Republic, it served as the residence for the Royal House of Organa, and the palace from which Queen Breha Organa governed the planet. Princess Leia Organa, the adopted daughter of Queen Breha and Bail Prestor Organa, spent her formative days in this castle, alongside her foster sister Winter, her aunts Tia Organa, Rouge Organa and Celly Organa and other members of the extended family. In 0 BBY, the Alderaanian government's rising prominence posed a threat to the growing power of the Galactic Empire. It was believed that the Royal Palace was obliterated along with the planet when Grand Moff Wilhuff Tarkin demonstrated the destructive force of the Death Star battle station on Alderaan. Despite the planet's destruction, a significant portion of the Palace survived within the rocky mass of Asteroid 7785.

The Royal Palace of Aldera was a relatively recent addition when considering the Alderaanian monarchy's long history spanning millennia. Its construction took place around 719 BBY in the mountains of Aldera, during the early centuries of the Great Peace of the Republic. For thousands of years before its construction, Alderaan's monarchs had presided over their court from various castles, notably including the ancestral home of House Panteer situated in the Glarus Valley.
During the final decades of the Galactic Republic, tensions arose among the nobles regarding the succession to the position of Viceroy, specifically whether it should be granted to the House of Organa or another family. In 28 BBY, this disagreement led to a crisis known as the Alderaan Ascendancy Contention, which was resolved by Jedi Watchman Jorus C'baoth. He quelled the dispute by uniting the Organas and the Antilles through marriage. Consequently, members of both houses resided in the Royal Palace, including Viceroy Bail Prestor Organa and his wife, Queen Breha Organa, formerly Antilles. However, the building remained the property of the Organas and was therefore called "House Organa."
After the devastating Clone Wars that lasted three years, the royal couple adopted the daughter of the deceased Senator Padmé Amidala. Princess Leia Organa spent her childhood in the Palace with her adoptive parents. As the galaxy was still recovering from the war's impact, Alderaan decided to completely disarm itself. The war frigate Another Chance was repurposed as an armory ship to store all of Alderaan's weapons. The frigate was programmed to continuously jump through hyperspace until the Council of Elders recalled it to Alderaan. The command chamber of the Another Chance was concealed within the Royal Palace of Aldera. Around the same time, demonstrations occurred near the Palace as the newly established Galactic Empire attempted to tighten restrictions on refugees seeking refuge on Alderaan. However, Alderaanian law enforcement managed to confine the protestors to a designated area, preventing any damage to the Royal Palace.

In 3 BBY, the Palace was the venue for the twenty-fifth anniversary celebration of the Ascendancy Contention, with Queen Breha and her husband Bail Organa inviting nobles from other planets. During this event, Count Adan Dooku of Serenno was murdered by Imperial agent Jahan Cross within the Palace walls. One year later, the Palace became a key location for the emergence of the rebellion against the Empire. Following the Cantham House Meetings, Bail Organa joined forces with Garm Bel Iblis of Corellia and Mon Mothma of Chandrila to form the Alliance to Restore the Republic. However, in 0 BBY, the Imperial Grand Moff Tarkin became suspicious of Bail Organa's loyalty and decided to set an example. Tarkin used the immense power of the Death Star, a moon-sized battle station equipped with a planet-destroying superlaser, on Alderaan. It was assumed that the Aldera Royal Palace was destroyed along with the planet and its millions of inhabitants.

Sometime later, a group of Rebels intercepted a message intended for Princess Leia Organa, stating that the Royal Palace had been discovered intact within the Graveyard, an asteroid belt resulting from Alderaan's destruction. Following this lead, the Rebel agents arrived at Asteroid 7785, where a considerable portion of the Aldera Royal Palace had indeed been preserved. Unbeknownst to them, the message had been sent by Darth Vader, the Supreme Commander of the Imperial Military. Vader's intention was to use this information to lure Leia Organa and other survivors of the Battle of Yavin to Alderaan, where the Imperial Captain Janus Bonn awaited them.
Vader's trap was set, but it didn't ensnare its intended targets. While exploring the ruined section of the palace, the Rebels encountered frightening holograms planted by the Imperials to instill fear in visitors. After defeating Janus Bonn and his forces, the Alliance agents discovered the hidden room from which the frigate Another Chance could be summoned.

Located at the heart of the city, the Royal Palace was situated on a gentle elevation at the edge of Aldera, overlooking a vast lake. It consisted of a complex of multi-story buildings and turrets, surrounded by ramparts and defensive moats filled with water. The Palace presented itself as a collection of shallow domes and tall, pointed spires that shone white and gold in the sunlight. A beautiful arrangement of orchards and gardens encircled the castle's outer perimeter, with several terraces built on different levels to provide the inhabitants with fresh air and light. The North tower featured a high balcony, offering an unobstructed view of the old moats and the palace's ramparts. Viceroy Bail Prestor Organa observed a series of demonstrations from this tower in 19 BBY.
The path leading to the main gates of the Palace wound through a blooming garden, lined with majestic dark golden trees. The front entrance itself was a wide wooden door adorned with intricate carvings. Other entrances to the castle included one in the curved South wall, another in the East wall, and another gate used by the royal family to access their private wing at the back of the castle.
Due to the prohibition of weapons on Alderaan, security measures around the palace were minimal. The palace was designed as an accessible place where any Alderaanian could request entry. Although the defensive moats had once been in use, they were considered outdated in the Republic's final decades. However, after the Clone Wars, the Royal Guards protected the Palace's exterior.

The multi-story building encompassed kilometers of winding corridors and a variety of bedrooms, ballrooms, and reception rooms. The Palace included a Grand Reception Room within a dome-shaped structure, a Grand Ballroom with a marble staircase, a throne room, a bridge-spanned reflecting pool, and Bail Organa's study, which overlooked the lake and was surrounded by gardens.
The palace's most formal room was topped by a domed ceiling and paneled with wood. It was devoid of furniture, and a massive sun-shaped lighting fixture hung from the ceiling. The Royal family would discuss their most ceremonial affairs in this space.
One of the Palace's entrances led to the First Hall, one of the many ceremonial chambers located within the Palace. The First Hall was long hallway decorated with statues, holo-art and sculptures. It provided access to a series of offices, most of which were occupied by low-ranking bureaucrats. One of those hosted the Alderaan Department of the Arts; various holoposters and four desks with data viewers were placed in that office. By walking past the suite of offices, visitors could reach the Grand Hall, an ornately decorated chamber, the Grand Hall in which the royalty of Alderaan held court. That second hallway was lined with pillars and featured a grand staircase that led to a lower level. Down the steps of the Grand Hall lay another series of chambers, which included a map room that contained a holomap of the Republican space. There were also a meeting chamber, a steam bath room, the dining hall and the lounge of the Council of Elders and the Amphitheater. That final room not only hosted the official gatherings of the Elders, but also contained the only possible access to the castle's best kept secret: the hidden chamber from which the armory ship Another Chance could be called back.

The private wing of the Royal family was located at the back side of the Palace. This private compound contained a room nicknamed the "inside-outside room." It was equipped with transparisteel doors marching along a wall so that the surrounding gardens would be seen in full display. The Royal family often gathered in this room in the mornings and evenings because the sunset light made it gleam like a flower. The bedroom in which Princess Leia slept had a window which opened on the palace grounds, and a tree with low-hanging branches allowed the young girl to go over the wall at night. Killik Twilight, a moss painting by the famous Alderaanian artist Ob Khaddor, usually hung outside the Princess' bedroom—although it could be borrowed for art exhibits. In addition to their bedrooms, ladies of the court like Rouge Organa could also possess their own boudoir.
Honored guests had the benefit of their own wing, which was located a long distance from the main reception room of the castle. One such guest suite was prepared for Count Adan Dooku shortly before his assassination. Those particular chambers featured a balcony, scarlet floor tiles, wide windows an a large, round bench settee.