The nobles, who were accused for the ignoble origin, had to go through the special procedure of proofing their nobility (deductionis nobilitatis) in the Polish-Lithuanian Commonwealth. They were required, according to the decision of the Diet in 1601, to submit a number of relatives-witnesses and documentary evidence during the annual deputy dietines and in front of the noble corporations’ representatives of that province from where the accused or his ancestors came from. A number of attestations, that were concluded in the 17th century as a result of successful proofs of nobility during dietines in Wisznia and Halicz, were known from the territories of Rus province. The understanding of family’s past, the former and current members of relatives of some privileged class, whose ancestral’s memory was stimulated by the threat of losing their social status, were reflected in these acts. The accusation of being ignoble had to push nobleman to restore his memory of the family, to reconstruct these ideas in a system of knowledge and to supplement them by the memory of his relatives and by documentary evidences. In the light of dietines’ attestations, the knowledge of ancestors and relatives, which differ in each case, was generally limited to three or four generations, usually no distant then grandfather’s generation (maximum great-grandfather). The memory of their ancestors from the female side was less profound (often no distant then grandfather), while from male side, due to property (hereditary) interest, it was supplemented with information from documentary records. A certain number of blood relatives, usually two or three dozen people and the representatives of older generations as well as coevals (cousins or second cousin and uncles) were known from the lateral branches. The relationship with them, in a mind of nobleman, was lined by the belonging to the descendants of any of the blood and affined relatives of his own ancestors. Preferably, the knowledge concerns men due to the patriarchal nature of noble families and perception of family as male (knight) corporation.