The founder and ancestor of the genus was Kaplon (or Cupan), the second son of Kond, who was one of the seven chieftains of the Magyars according to Anonymus, author of the Gesta Hungarorum.

Among others, the Sztáray, Barlabássy, Bagossy, Csomaközy, Vadai and Vetési families were also from that clan and had spread northward, eastward and southward.

The 13th-century chronicler Simon of Kéza in his work Gesta Hunnorum et Hungarorum says that one of the chieftains of the conquest was Kond (or Künd), who settled in the Nyírség region.

[5] Péter Németh emphasized the uncertainty that the Kaplons was really the original and ancient occupying kindred at the time of the Hungarian conquest over the region.

According to the contemporary records, he argued, the Kaplon clan acquired the surrounding lands over their ancient estate Kaplony only in the second half of the 13th century, for instance, Vetés (Vetiș), Károly (Carei) and Bagos (Boghiș), the namesakes of noble families breaking out of the genus.

His widow and his sons – Simon (I) and Michael – were involved in a lawsuit against castle folks of Szatmár, who claimed that the late Andrew unlawfully seized portions of lands in Vada from them.

[9] The three brothers – Peter (I), Endes and Andrew (II) – and their cousin Mike (son of Michael) reserved their right for a portion in Bere, which came into the possession of another family, in 1291.

However, they were unable to receive Olcsva, because the local (in nearby Szamosszeg) official of the rebellious Beke Borsa refused to hand over it.

Andrew (II) and his four sons were granted Olcsva (thus the first Károlyis was also referred to as Olcsvais in early times) with the surrounding land Mikecsalános.

Peter's five sons further divided their inherited possessions among themselves in 1325 and 1341, which led to the formation of the various aforementioned noble families named after their centre settlements.

Through this marriage, Jakó's branch acquired several landholdings in Ung and Zemplén counties, since Peter, Catherine's father had no male descendants.

In the next year, Agnes donated these estates to their daughters and grandsons, establishing the Nagymihály lordship, an important fortune of the Kaplon clan.

Peter and Agnes donated another villages – Vinna (Vinné), Zalacska and Tarna (Trnava pri Laborci) – surrounding the aforementioned estates to their daughters still in that year.

[21] Jakó and Andrew began to establish Nagymihály lordship, an important centre of their estates, which laid in the borderland of Zemplén and Ung counties in the area between the rivers Laborec (Laborc) and Szeretva (or Cserna).

[18] Sometime in the last third of the 13th century, they built the castle of Nagymihály, a fortified stronghold in the region (present-day ruins, belongs to Vinné).

[23] In 1279, Ladislaus IV donated them the fort of Jeszenő (today Jasenov, Slovakia) with the surrounding forest as a "lost heritage".

[26] Following the extinction of the Árpád dynasty and the era of Interregnum (1301–1310), Amadeus Aba, as a powerful oligarch, ruled de facto independently the north-eastern region of the Kingdom of Hungary, including Ung County.

During the Abas' rebellion against Charles I, their troops commanded by Dominic Csicseri pillaged and occupied the castle of Tiba from the Kaplons.

[25] However, the branch proved to be quite numerous in the 14th century, which led to the fragmentation of the unified Nagymihály property: Andrew (I) and Jakó (II) had altogether five sons, ten grandsons and fourteen great-grandsons who also begot offspring.

As a result of the first divisions (1335–1337), seven separate lordships were formed by 1350, which became the basis of the emerging noble families (Tibai, Ördög, Lucskai, Ödönfi, Bánfi, Pongrácz and Jakó's Nagymihályi kinship).

The Nagymihályis possessed significant portions throughout in Ung County, for instance, in Szobránc (Sobrance), Jeszenő, Alsóribnice (Nižná Rybnica), Felsőreviscse (Veľké Revištia), Felsőtiba and Baskóc (Baškovce).

John's half-brother James (II) functioned as castellan of Borostyánkő (today Bernstein im Burgenland, Austria) in 1385.

Despite being from one of the poorest branches, Albert rose to become one of the most powerful barons during Sigismund's reign, due to his regular military engagements and influential allies.

[41] Andrew exchanged his estates Varsány and Emőcsteleke in Szabolcs County for Géres, Őrös (present-day Veľký Horeš and Strážne in Slovakia, respectively) and Gerebse (today a borough of Strážne) in Zemplén County to the three sons – Nicholas, Stephen and Vid – of the late Paul Gutkeled in 1310.

[44] In the next year, Andrew exchanged the newly acquired villages – Őrös and Gerebse – for Szürnyeg and Kiszte in Zemplén County (today Sirník and Kysta in Slovakia, respectively) with members of the Tárkányi family.

As a loyal partisan of King Charles I, Andrew participated in the sieges of Komárom and Sempte (today Šintava, Slovakia) against the rebellious Matthew Csák in 1317.

[45] According to the document, the unidentified widows of Dés (I) and his son Denis declared that the latter bequeathed the estate to his sisters shortly before his death; Proxya (Euphrosyne?)

Its member, John, son of Andronicus (I) sold his inherited estate Szántó in Zala County for 110 marks to his "relative", cleric Zlaudus Ják in 1236.

[8] John had an unidentified sister, who was the widow of a certain Peter, son of Fuurh in 1248, when she was granted her dowry by the cathedral chapter of Esztergom.

It is possible that he supported the rebellion of the Aba clan and Peter, son of Petenye in the region, therefore Charles I confiscated Parics Castle from the family in 1318 and handed it over to Philip Drugeth, his faithful confidant and the new de facto lord of Northeastern Hungary, in the next year.