Polish Problem

King Boleslaw III King of Poland is father of Kazimierz II 'the Just', =
Duke of Sandomir etc.=20

Kazimierz II married about 1163 Helene von Znaim.=20
According to ES Freytag von Loringhoven (Volume II Tafewl 83) Kazimierz =
II was married only once and they had the following children

1164 a daugther who grew up and married
ca,1165 Kasimir
ca.1168 Boleslaw

Peter Stewart...

These children were from a first marriage, to an unknown wife, according to
Wlodzimierz Dworzaczek in _Genealogia_ (Warsaw, 1959). The daughter was
married in 1178 to Vsevelod, grand prince of Kiev, and died before him,
probably in 1194. The two sons both died young, Kasimir as an infant on 2
March 1167, Boleslaw on 16 April 1182.

1186 Leszek V
1187/88 Konrad I

Peter Stewart...

And these were from the second marriage, ca 1185/6, to Helena who may have
been daughter to Rostislav I Mikhail, prince of Smolensk or Konrad, prince
of Znaim.

Peter Stewart

This shows a huge gap between 1168 and 1186