From Medlands:
There is some chronological difficulty with the parentage of Robert de Lisours. The name “Lisours” suggests a connection with Fulk de Lisours who is named above. However, given the death of his daughter’s first husband in 1163 (see below), it is difficult to imagine Robert being born later than 1120 at the latest. If that is correct, he could not have been Fulk’s son by his known wife Alix d’Auberville, given that the latter was declared as 50 years old in 1185 (see above). This affiliation would only seem to work if Alix’s age was under-declared by at least 30 years, which seems impossible if she had three unmarried daughters still of marriageable age in 1185. Three possible solutions are suggested:
(1) Robert was Fulk’s son by an earlier marriage, although that would mean that Fulk himself was born much earlier than appears consistent with the chronology of the Engaine family.
(2) Robert was the son of Vitalis [I] Engaine.
(3) Robert was a member of the previous Lisours family, maybe a relative of the supposed wife of Vitalis [I].
so FULK de Lisours (->1166) cf Fulk de Lisures
s/o VITALIS [Viel] [I] Engaine (->1130) & NN de Lisours, d/o WILLIAM de Lisours
x ALIX d’Auberville d/o NN ([1135]->29 Sep 1189)
Removing present parents: Foulques d'Aulnay, II & Albreda NN as well as son - Robert de Lisures