Dear Lawrence,
Yes, I've read that too - Normandy!
There were also "Bohuns" in Ukraine - I'll continue searching for info regarding this.
I've researched my own family background and my wife's.
My grandmother was a "Jablonowskie" descended from Count Auguste Jabonlowskie, who was from mixed Polish-Ukrainian background and who fought the Turks.
There is a statue to him in Cracow and the Jablonowskie family has a chapel in Czestochowa.
I'm proud to say this family goes all the way back to St Olha and St Vladimir (and St Alexander Nevsky).
As for the Scots, in fact the Scots Presbyterians loved to fight Catholic armies!
St Theodore Ostrozhki also adopted war tactics from the Protestant Hussites (General Jan Zizka) in his battles with the Poles.
There was also the class aspect - lower class Poles fought on the side of the Kozaks and upper class Ukrainians fought on the side of the Poles.
The leader of the Poles who destroyed the Kozak army at Berestechko was a Ukrainian "Janissary" or traitor - his sword, by which he killed his own people, is on display at a Polish museum today.
Alex