You're right Patrick but I could not refrain from addressing this sub-thread on Scots in Poland :)
With regard to Hugo O'Brien de Lacy...his ancestor was a certain Mary de Lacy, sister of general Count Maurice de Lacy of Grodno (Polish territory occupied by Russia). The general had no children and therefore it was arranged that the husband of his sister Patrick O'Brien would adopt his wife's name or rather extend his own. That is the origin of the family name O'Brien de Lacy (also spelled de Lascy, de Lassy). The general's nephew inherited most of his fortune.
The de Lacy family has Norman roots. Numerous members of this family left Ireland in the 17th century and hence the presence also in Eastern Europe.
Up until 1939 the O'Brien de Lacys owned an estate in Augustówek (now Belarus) - once a gift from Catherine II for general Maurice de Lacy.
http://www.pinakoteka.zascianek.pl/O...Augustowek.jpg
Hugo's father was a lieutenant in the Polish army before the war. Hugo's sister Margaret lives in Warsaw.
I hope this closes up the speculations :)