Aba is a noble kindred (genus) of the Kingdom of Hungary. Their ancestors may have been among the tribal leaders of the Kabars (three nomadic tribes that joined the tribal federation of the Magyars in the 9th century). The Gesta Hungarorum ("The Deeds of the Hungarians") mentions that Ede and Edemen, the Abas' ancestors, received land possession around the Mátra Mountains, especially in Gyöngyöspata – Heves County, after the conquest of the Carpathian Basin by the Magyars (around 895). The Gesta Hunnorum et Hungarorum ("The Deeds of the Huns and the Hungarians", 1282–85) connects the family to Attila the Hun.
Csaba was Attila's legitimate son by the daughter of the Greek emperor Honorius. Csaba in turn had two sons, Edemen and Ed. Edemen entered Pannonia with his father's and mother's great entourage (his mother being a Chorasminian) when the Hungarians came back for the second time, whereas Ed remained in Scythia with his father. Csaba is the ancestor of the clan of Aba.
Samuel Aba was the most prominent member of the family who became King of Hungary (1041–1044). The gens may have been named after him. Amade Aba is another prominent descendant of the family; he held several castles and possessions on the northern and north-eastern parts of the kingdom in the first decade of the 14th century.
The gens divided into several families in the course of the centuries.
Today there are nineteen noble families that directly descend from the Royal House of Aba, and belong to Clan Aba – “Genus Aba”. They are: Athinai, Báthory of the Clan Aba, Báthory de Gagy, Bertóthy, Budaméry, Csirke, Csobánka, Frichi, Gagyi, Hedry, Keczer, Kompolthi, Laczkffy de Nádasd, Lapispataky, Rhédey, Sirokay, Somosy de Somos, Vendéghy and Vitéz.
Various members of the Rhédey von Kis-Rhéde branch of Genus Aba held many royal offices and acquired many hereditary titles. Among them – Voivod (Dukes) and Princes of Transylvania, Counts of Rhédey von Kis-Rhéde, Hereditary Count Palatines of the Holy Roman Empire, Papal Hereditary Count Palatines of the Lateran Palace and Countess von Hohenstein.
In the case of Countess Claudine Rhédey von Kis-Rhéde - Countess von Hohenstein: Prince Francis of Teck was later created Duke of Teck. He married Princess Mary Adelaide of Cambridge, a granddaughter of King George III and became a member of the British Royal Family. His only daughter, Mary of Teck, married Prince George, Duke of York in July 1893, becoming Queen-Consort on her husband's accession to the throne in May 1910. The current British monarch, Elizabeth II is Mary's granddaughter, and thus Claudine's great-great-granddaughter.