A place name
Surname references classify Aquino as toponymic: it comes from the town of Aquino in the province of Frosinone, Lazio, the ancient Latin Aquinum.1 Families who held land there, or who came from there, were known as "of Aquino" (d'Aquino in Italian, de Aquino in Spanish). In time the phrase hardened into a surname.2
The Lombard counts of Aquino
The noble family traced itself to Rodoaldo (Radoaldo), lord of Aquino in the 9th century, when the area belonged to the Lombard duchy of Benevento. The philosopher Benedetto Croce described the family as being of Lombard blood.23 By about 970 the sources name an Adenolfo, count of Aquino and Pontecorvo.3
Over the following centuries the d'Aquino were drawn into the conflicts between the papacy and the Empire, and between the Normans and the Hohenstaufen. Thomas II d'Aquino, count of Acerra, married Margaret of Swabia, daughter of Emperor Frederick II, in 1247.3 The family counted among the Seven Great Houses of the Kingdom of Naples, alongside the Acquaviva, del Balzo, Celano, Molise, Ruffo and Sanseverino.3
Several lines are documented: the main line, whose heiress carried its titles into the d'Ávalos family; the counts of Belcastro; the barons of Roccabascerana; the patricians of Cosenza; and the patricians of Tropea, which died out in the mid-20th century.3
Saint Thomas Aquinas
The family's most famous member was born around 1225 at the castle of Roccasecca, son of Landulf of Aquino. Thomas joined the Dominican Order against his family's wishes, became the most influential theologian of the Middle Ages, and died at Fossanova on 7 March 1274. He was canonized on 18 July 1323, and his feast day is 28 January.4
His name made "Aquino" a name of faith as well as a name of lineage.Editorial summary
A devotional surname
This is the key to understanding the many Aquino families of the Americas and Asia. FamilySearch's Philippine surname guide notes that the name is often devotional, given in honor of Saint Thomas Aquinas.5 Brazilian surname references likewise attribute the name's popularity to his influence.6 In the Dominican Republic, the 1812 census of San Francisco de Macorís records a child baptized Tomás de Aquino, an example of the saint's name passing to ordinary families as a given name. Names like this could later become surnames.7
Bearing the name Aquino is not, by itself, evidence of descent from the Italian counts. Only a documented paper trail can show that. Most Aquino lines in the Americas should be researched as independent family histories.
The coat of arms
Spanish heraldic references describe the Aquino arms as banded of twelve pieces, gold and red (bandado de doce piezas, de oro y gules).1 Heraldry belongs to specific lineages, not to everyone with a surname. The arms below are shown for historical interest only.