Lucas I is the earliest known member of the gens (clan) Péc, which had large-scale possessions in several counties of Transdanubia, in addition to other parts of the Kingdom of Hungary.
They originated from Sokoró Hills (Győr County), their ancient clan estate laid in present-day Felpéc and Kajárpéc.
19th-century historian Mór Wertner considered all of them as a single person in his various academic works, albeit with various sturdiness.
Subsequently, he slightly modified his viewpoint, and considered Lucas, who functioned as ispán of Hont County, was "probably different person".
Historian Attila Zsoldos analyzed further the question: he separated Lucas, the ispán of the Bakony royal forest too, as its office-holders came from a lower social status in the era.