According to Croatian historian Antun Nekić, Thetun (Tétény or Tetenj) was a real or fictional ancestor of the kindred, however, no historical data has survived about him.
By the early 13th century, the family centered around the estate Peker or Pukur nearby the namesake river in Slavonia, near present-day Daruvar in Croatia.
[3] While Hungarian historian János Karácsonyi rejected to utilize those genealogical data which appear in the 14th-century non-authentic charter,[4] Antun Nekić argued the text perhaps contains useful information regarding the Tétény kindred.
[6] It is plausible they possessed the initial ancient landholdings around Tétény in Central Hungary (present-day Budafok-Tétény, a southwest district of Budapest), including Sóskút and Tordas.
For his faithful service, Marcellus was granted landholdings and estates across the Drava (including the extended lordship of Peker and the surrounding Osuvak), which he tried to expand by purchasing.
[12] Before 1228, he was involved in a lawsuit with the Vajk kindred over a possession called Keresztúr, which laid between Peker and Toplica (present-day a borough of Daruvar in Croatia).
He also handed over his all purchased estates beyond the river Drava in the area east of Đakovo – Daróc (present-day Vardarac, Croatia), Ködmen (Cudmend), Rücs (Ručevo) and Donát in Valkó County – to the duke, thus he was able to retain his portion in the inherited lordship of Peker.
[11] Fabian activities can be discerned through the long-term dispute he managed with the Benedictines from Pannonhalma Abbey, says in a document from 1234 that, since he did not have a seal himself, he borrowed one from his brother Marcellus.
[18] It is plausible that Peter was that family member, who built the castle of Dobra Kuća (Hungarian: Dobrakucsa), laid near Daruvar, on the top of the Papuk mountain, which later became a royal property in 1335.
[19] At the end of 1278, Conrad Győr filed a lawsuit against Paul I due to a damage estimated at 200 marks that the latter caused him in the village of Thopoz in Baranya County.
Despite the verdict, the estate remained in the hands of the Tétény clan, possibly due to Peter's political rise, who thus was able to protect family interests very successfully.
For their loyalty during his imprisonment, Ladislaus IV donated the estates Aszuág (Ozyag; in the area between present-day Donji Miholjac és Sveti Đurađ in Croatia) and Gajul on the bank of river Ilova to Peter and his brothers in April 1281; both lands were formerly considered inherited estates of the Tétény clan, but were confiscated and attached to Baranya County during the ascension of Béla IV.
After a lengthy dispute, his sons – Lawrence and Nicholas – appeared before the collegiate chapter of Buda (a place of authentication) on behalf of their uncle Kemény in 1286, and paid off the dower (i.e. a portion in Peker estate) of the unidentified widow of the late Abraham to the Dominican nunnery at Margaret Island, in accordance with her last will.
In exchange, the nuns renounced any pretensions to the Peker property and returned to Kemény all documents relating the estate which were in the possession of Abraham' widow until her death.
Upon their request, the monarch confirmed their right of ownership over Aszuág in October 1290, despite that the influential Kórógyi family (John, son of Ladislaus) also laid claim to the property.
The Kórógyis – Philip and Demetrius – protested against their elder half-brother John, who had control of the Barázda estate (near Osijek) to the exclusion of his family members with Lawrence and Nicholas in 1294 (i.e. Kemény died by then).
During the conflict between the Kórógyis and Pekris, Lawrence sought assistance from his maternal cousins, Julius and Peter Siklósi, who financially supported him to recover Aszuág.
The reason for the dispute is the destruction of an undisclosed property, the capture of people, and other atrocities committed by the warring parties, which apparently reached the amount of 20 marks, on the basis of which James, together with Sayan, was to take an oath before Henry.