House Atreides is a fictional noble family from Frank Herbert's Dune novels.
House Atreides is one of the great houses of the Imperium, the feudal interstellar empire that forms the backdrop to the Dune novels. This noble house hailing from the water planet of Caladan employs unlikely methods in its struggle to secure the spice of Arrakis: noble spirit, just ways and unfailing virtue. Ruling its homeworld Caladan for generations with justice and generosity, House Atreides has perfected a form of government that results in a well-organized society and a spiritually satisfied people. Little wonder that Caladan is the lush, prosperous paradise that it is. However, the House was also proficient in war; it had even developed an Atreides battle language (in the film version, this language is presented as a system of hand signals, whilst the book also includes a spoken language).
House Atreides is ruled by a duke. At first in the Dune novel the Duke is Leto Atreides. His concubine was the Bene Gesserit acolyte Jessica, who produced for him the son Paul Atreides.
Leto's son Paul Atreides is the main character during the first novels. He fights alongside the native Fremen in the war on Arrakis and finally becomes both the Fremen Messiah and Emperor of the known universe.
As Paul Atreides is lost in the desert twelve years later, his sister Alia inherits his title as the Duchess of Atreides and as Regent of Paul's empire until his children come of age. Eventually, Paul's son Leto II becomes Duke of House Atreides (to wit, "I am House Atreides"---Leto II), and God-Emperor of Dune.
Leto II had no heirs; however, Paul's only other child to survive to adulthood (a first child named Leto II was killed in infancy by a Sardaukar soldier), Leto II's twin sister Ghanima, mated with Prince Farad'n Corrino and produced a long bloodline, manipulated in no small part by Leto II. This resulted, 3,500 years later, in the birth of Siona Atreides, who possessed genes that made her invisible to prescient oracles. 1,500 years after this, another descendant of Siona Atreides was Miles Teg, commander of the military forces of the Bene Gesserit, who bore a remarkable resemblance to his ancestor Duke Leto I. Teg's daughter was Darwi Odrade, a Bene Gesserit sister that eventually became Mother Superior of the Bene Gesserit order.
Political, Economic and Military power
At the beginning of the prequel trilogy, Atreides power was capable but limited, it was secure on Caladan, had an uncommon reputation for honour and decency in politics. While Caladan produced sustainable resources (Pundi Rice) and some luxury items (Caladanian wines were the best wines in the known universe) it does not have the economic power of Ix or Arrakis (Under Harkonnen stewardship).
During the period of Duke Leto's rule, use of combination of Thufir Hawat, Gurney Halleck and Duncan Idaho training Atredies troops brought their soldiers to a quality approaching that of the Sardaukar, with the ability to expand the force to a size matching the Emperor's army.
Meanwhile Leto's actions as well as words throughout his reign move him into a very popular political position. While not having the economic strength of Corrino, Shaddam IV sees a rising threat to his power matched with his inability to produce a male heir (due to the manipulations of the Bene Gesserit to produce a power vacuum into which they would be able to move with their Messiah (to be born to Jessica's daughter and Feyd-Rautha Harkonnen).
In an effort to counter the Atredies rise, an alliance between Harkonnen and Corrino is formed to eliminate House Atredies by trapping them on Arrakis (Dune). However realising the trap he is entering, Leto attempts to forge an alliance with the Fremen. Although Leto does not live to see his vision of "Desert Power" his son turns the Fremen into the greatest army the universe had seen to date. This army forms a new Jihad that spreads out across the universe establishing the Atreides rule of the Imperium (centred on Arrakis instead of Kaitain).
Leto II increased the control over the empire with his Fish Speaker army in order to repress humanity as part of the plan for his Golden Path.
While no longer a single entity the Shaitain descendents of Leto continue to influence humanity until the sterilisation of Arrakis by the Honored Matres. In spite of the death of all but one of these worms, the surviving part of humanity is in part descended from Siona Atreides and so while Atreides in name are a memory, their legacy will continue on as long as humanity.