The place-name Károly is derived from the given name of the identical form (which first appeared in the form of Karul in 1262). The origin of the given name after which the settlement was named dates back to the karvul-karvaly (sparrow-hawk) word of Turkish origin, which possibly served as the totem bird of the Károlyi branch of the Kaplony Clan. The sparrow hawk is also featured in the coat of arms of the Károlyi counts.

The city founders were Károlyis from the Kaplony Clan which was present at the Conquest of the Carpathian Basin. The city’s name first appears in a charter dating from 1320, yet its actual settling took place much earlier. In 1335, it is mentioned in relation to Szatmár County “in provincia Nyír” about a certain “Nogkorul”, yet this was the ancient domain of the Gutkeled Clan. This name exists to this very day as the Karuly border name in border region of Szaniszló. It was by no means a major settlement in the 14thcentury. Its streets and tiny, adobe and thatch-roofed houses were situated around the Károlyi mansions along the roads leading to the neighbouring settlements. A charter from 1389 mentions three streets: Berueucha (Börvelyi street), Bobaducha (Bobáld street) and Wyucha (Új street). At the time, the Vadai mansion was in a separate location along with the structures built around it (its name is still preserved by the street known as Vadai-köz, which is now Gheorghe Bariţiu street). Despite the above, the small settlement already played a pivotal role in the Károlyi domain by the early 14thcentury, which is proven by the fact that in 1346, the sons of András Károlyi received market rights from King Louis I of Hungary for all Saturdays of the month. In 1387, as the country’s protector, Sigismund Prince-elector of Brandenburg granted the rank of Ispán (jus gladii) to the sons of Merhard Károlyi, László and András. In the same year, King Sigismund granted nation-wide market rights to the sons of Merhard Károlyi on their domain named Károly in Szatmár County. In the 15thcentury, the city became the holding of the Károlyis, confirmed by a royal grant in 1419. In 15th-century documents, the city’s name is listed as “oppido Karol”. The right of holding weekly and nation-wide markets was ensured by further letters of donation. In 1477, King Matthias granted annual and weekly market rights to Ladislai Lonc de Karolna: Tuesday was designated as the weekly market day, whilst the nation-wide market was schedule for Dorottya day, followed by two additional nation-wide markets granted in 1482. From the 15thcentury onward, the Károlyi family and the Károly castle played a major role in the life and development of the city. In 1482, Lancz László Károlyi builds a “stone house” against Turkish incursions. In 1699, Sándor Károlyi converts the castle before Count József Károlyi tears down the old castle in 1794 and builds a palace on its spot, which Count István Károlyi converts into a fortification in 1894. The palace still stands to this very day (used as a hospital during World War I and subsequently serving as a paramilitary youth training school and later as a zoo-technology secondary school after 1945 before housing the City Museum and Library). In the 16th-17thcenturies, the city was more characterized by decay than development. Apart from the Turkish raiding and pillaging, the Labanc and Kuruc battles also take a toll on the settlement. This is verified by László Károlyi’s notes from the year 1670 (“…by the Grace of God, Károly’s castle remains, yet its city was uprooted by Prince György Rákóczi and its inhabitants were scattered… They drove off nearly one thousand of my sheep from Károly, with the Károly palace as my only remaining fortune…”). The city and its vicinity suffered the heaviest losses and the greatest damage during Rákóczi’s War of Independence, with Szatmár County as one of its sites. Many villages are abandoned, the population flees the area and turns Kuruc or falls in the battles. The eight years of warfare come to an end with the Treaty of Szatmár in 1711. This marks a new period in the history of Nagykároly: the age of settling. Count Sándor Károlyi acquired vast estates in the area and settled Swabian Germans in the abandoned villages and barely populated city of Nagykároly. The first Swabian settlers arrive in 1712, while the last 45 families settle in the city in 1774. From 1712–1774, 466 Swabian families settled in the city from Würtemberg, Biberach and Ravensburg, Germany. The new settlers populate two new city districts: the Swabian quarter and the Master quarter. The remaining population of the neighbouring villages also settles in Nagykároly. The Romanian population of Bobáld populates Hajdúváros (three streets: Nagyhajdúváros is now Vasile Lucaciu street, Kishajdúváros is now Haiducilor street and Hajdúköz is now Titulescu street). In 1740, Count Sándor Károlyi settles a large number of Jewish people in the city, granting 50 inner city lots to them on his estate next to the palace. This leads to the establishment of the Zsidóköz (Jewish Quarter). 1483 Jews live in the city by 1847, mostly traders and craftsmen. By the end of the 18thcentury, the city consists of the following districts: Mester quarter, Nagyutcai quarter, Swabian quarter, Újváros and Hajdúváros, all of which had separate “governing authorities” or prefecture. Separate city districts include the Zsidó-köz (Communitas), Cigányvég (with a separate Voivode) alongside the free estates of noblemen: the Vadai Hall numbered 60 buildings, whilst Tömpe Hall had 12 houses. Apart from their noble estates, there were also so-called “inscriptional noble estates”, which fell under noblemen’s authorities, such as the Fekete, Asztalos, Csiszár, Irinyi, Szuhányi, Jasztrabszky, Luby, Mede and Szaplonczay Halls. Not only did the city’s area expand, its population increased as well, along with the development of its industry and commerce. In 1784, craftsmen pursued 54 different industries in the city, with 370 tradesmen who formed guilds (80 wool-makers, 73 boot-makers, 19 potters, 27 tailors, 26 cloth-makers, 17 cobblers, 18 shoe-makers, etc.). In 1725, Count Sándor Károlyi settled a monastic teaching order (Piarists) in the city, building them lodgings and a school, where they began teaching in 1727 (the first principle of the school was Gábor Bentsik rector and parish-priest, whilst its last principle was Béla Kovács in 1948). In 1754, Count Ferenc Károlyi establishes the first printing house of Szatmár County in the city. The first pharmacy opens its doors in 1765. In Hungary, the last witch-trials of the 18thcentury took place in Nagykároly. In 1730, Borka Tóth “…from Sarollyán… was sentenced to death by fire and burned alive in Nagy Károly”. In 1745, “Pila Rekettye and Anna Varga, women of Császló were exposed to torture due to the statements of their peers and were subsequently burned alive in Károly”. In the 19thcentury, the city continues slowly developing, yet this mainly entails the reconfiguration of the interior properties. In 1850 (as Elek Fényes wrote in his work entitled the Geographical Dictionary of Hungary) “Károly (-Nagy) is a populous and fair country town… It has a population of 11,284 souls, mostly Hungarians and Germans, Jews, Romanians and Russians to a lesser extent. As far as religion is concerned, 4792 were Roman Catholic, 2000 Greek Catholic, 248 Lutheran, 2258 Reformed and 1768 Jewish. There city has a Roman Catholic parsonage, a Piarist boarding school, Reformed and Lutheran congregations, two Greek Catholic churches, one belonging to the Romanians and the other to the Hungarians and Russians, one Synagogue, postal office, a salt house, regular school, royal grammar school under the supervision of devout fathers, a printing house and many guilds of craftsmen and tradesmen. The city’s weekly and nation-wide markets are particularly renowned for their grain, cattle, horses and swine… The private houses are mostly of a low build…” In 1848, the city established a council, yet this only entered into force in 1876, when József Hegedűs became the city’s first mayor. The city also adopted its old coat of arms at this time. New city districts were built in the 1920s: Petri-telep, Teremi-telep and Kaplonyi-telep, along with the development of Galambos-telep and Tisztviselő-telep. Until the 16thcentury, the city’s population most likely consisted of Hungarians after which the settled serfs made the city’s ethnic mix more varied. In 1779, the Dominion of Antal Károlyi and the country town of Károly, had the following composition: Hungarian, Russian, Romanian, Tóth (Slovakian), Jewish, German and Swabian nationalities. Landed farmers in the number of 939, Houses of Hajdúváros 72, Housed cotters in the same area 20, Houses of Jews 32, Total of 1063. The city’s population developed in the following manner over the last two hundred years: 7823 in 1789, 11,055 in 1820, 11,284 in 1830, 12,754 in 1870, 12,523 in 1880, 13,475 in 1890, 15,382 in 1900, 16,078 in 1910, 16,042 in 1930, 16,780 in 1956, 19,042 in 1966, 21,061 in 1971, 26,372 in 1992, 23,182 in 2002 and 21,112 in 2011.