Archducal Palace of Ecaz: seat of the Mahogany Throne

The Archducal Palace of Ecaz was the seat of government on the planet Ecaz and the residence of the Archduke of House Ecaz, sovereign of the entire Ecazi system. It housed the Mahogany Throne, the ancestral seat of the Archdukes, and it was the place where Archduke Armand Ecaz received Duke Leto Atreides I and his household to settle the marriage that would begin the War of Assassins of 10,187 AG. Twice in three generations the Palace passed out of Ecazi hands, once to rebels who expelled the Archduke outright and once to a rival Great House that reduced the throne room to cinders from orbit. (Dune: House Harkonnen; Paul of Dune)

The seat of a sovereign House#

Ecaz was the fourth planet orbiting Alpha Centauri B, a world of jungles, high plateaus and bloodwood forests whose exports made it wealthy out of all proportion to its size. It produced elacca wood and the elacca drug, the truth serum verite, sapho, pleniscenta, semuta, the krimskel fibre drawn from the hufuf vine, and the fogwood that could be shaped by human thought alone, which earned the planet its name as the sculptor's paradise. Its ruler held the rank of Archduke and stood above the Dukes of the Ecazi continents, and the Archducal Palace in the capital was where that authority sat. (Dune; Paul of Dune)

The building was more than an administrative centre. Inside it stood the Mahogany Throne, the legendary seat of the Archdukes of House Ecaz, an object that carried the same weight for the Ecazi line that the Golden Lion Throne carried for House Corrino. Whoever held the Palace held the throne, and whoever held the throne was understood to speak for the Ecazi system. (Dune: House Harkonnen)

The Ecazi Revolt#

That equation was tested when Emperor Elrood Corrino IX contracted an impulsive marriage to Habla of Hassika V. The match set off open hostility towards the Imperium, and Ecaz became the centre of the rebellion that followed. The rebels expelled Archduke Ferdinand Ecaz from his own capital and took the Palace with it. (Dune: House Atreides)

Elrood's response was inadequate to the scale of the rising. His Sardaukar alone could not break the rebels, and the Emperor was reduced to asking the Great Houses of the Landsraad for troops. House Vernius and House Atreides answered, sending armies under their own lords, Earl Dominic Vernius of Ix and Duke Paulus Atreides of Caladan. Between them and the Sardaukar the rebellion was broken and Ferdinand Ecaz was placed back on the Mahogany Throne. (Dune: House Atreides)

Ferdinand held it until his death, and the Palace and the throne passed to his son Armand. The alignment that saved the Palace outlived the revolt. Armand later counted the Atreides Duke a friend and an ally, offered him first his eldest daughter and then his youngest in marriage, and it was House Vernius and House Atreides that stood beside Ecaz in its last war. (Dune: House Atreides; Dune: House Harkonnen; Paul of Dune)

Burned from orbit#

The second loss was violent and gave nothing back. During the first War of Assassins between House Ecaz and House Moritani, Viscount Hundro Moritani launched a surprise attack on Ecaz and bombarded the Archducal Palace. The strike burned out the site of the Mahogany Throne completely, leaving ash where the ancestral seat had stood. Armand Ecaz and his three daughters escaped into the jungle, though only barely, and it emerged later that one of them, Mesa, had died in the bombardment. (Dune: House Harkonnen; Dune: House Corrino)

That attack was of a piece with the rest of the Viscount's conduct in the feud, which included the assassination of the Ecazi ambassador Bindikk Narvi by his Grumman counterpart Lupino Ord at a banquet in Arrakeen, and the public execution on Grumman of Armand's eldest daughter Sanya and his brother. The destruction of the throne was the part that could not be answered with a duel. A House can replace an ambassador. It cannot replace an object that has been the physical proof of its legitimacy for centuries. (Dune: House Harkonnen)

The Palace was rebuilt. By the years immediately preceding the second War of Assassins the damage had been repaired for some time, and it was in the restored building that Armand received the man who was to become his son in law. Leto Atreides came to Ecaz with his household to discuss the marriage of his host's last surviving daughter, Ilesa, and it was there that the Archduke extracted Leto's agreement to conduct no treaty and no trade with Grumman. (Paul of Dune)

Vidal's false succession#

The Palace changed hands a third time without a shot being fired. When the wedding at Castle Caladan ended in Ilesa's death and the maiming of her father, Prad Vidal, Duke of the Ecazi continent of Elacca and a secret ally of House Moritani, announced across Ecaz that the Archduke and his heiress had been murdered along with several members of House Atreides. On that basis Vidal declared himself the successor and installed himself in the seat of government. (Paul of Dune)

The lie held only until Armand arrived home alive, escorted by the Atreides army. Ecazi civilians fled the capital in panic, believing they were being invaded, and the confusion at the Palace was worse still. Ships lifted from the Archducal hangar and ran for Elacca, carrying Vidal and his supporters to his estates, where he intended to hold out and provoke a civil war. He did not get one. Leto Atreides went in personally with Gurney Halleck, took Vidal in his own fogwood fortress and killed him under the forms of kanly, after which the Elaccan rebels submitted and Armand assembled his forces at the Palace for the march on Grumman. (Paul of Dune)

The last Archduke#

Armand Ecaz came out of that war on the winning side, and it profited him nothing. He came back to the Palace armless, without heirs and the last member of his House. Years later, after Emperor Paul Atreides addressed the Landsraad on Kaitain and demanded the submission of the noble families, the old Archduke sent his surviving Swordmaster Whitmore Bludd to Arrakis with a message. He had been a friend of Paul's father, he was old and heirless, and he yielded his domain to the forces of Muad'Dib's Jihad. (Paul of Dune)

Paul accepted, took Bludd into Imperial service as an architect, and Armand withdrew from politics to his estates on Ecaz. The Mahogany Throne was already gone by then, and the Palace outlasted the line it had been built to legitimise. (Paul of Dune)