Kresy - means borderlands - used to define Polands eastern border during the Polish-Lithuanian Commonwealth and between the two World Wars.

The borders were annexed by the Soviets in 1939 and incorporated into the Soviet republics of Lithuania, Belarus and Ukraine.

Kresowiacy : Poles that lived in these lands.

The Marczaks that came to Manchester England came from the hamlet of Ulanska Dola near Targovica in the Wolyn between Lutsk and Dubno.

( For Anglofiles Wolyn pronounced Vowin W= v and L with a dash through it = w , O with a dot over it = u,

so Lwow is pronounced Lvuv and Krakow is pronounced Krakuv )

Jureks wife Marisia came from the village of Jaksza near Pinsk in Polesie.

From around 1386 to 1772 nearly 400 years The Polish Lithuanian commonwealth was the largest country ruled by a single king in all of Europe.

It's territory extending almost to Smolensk and Kiew.

The centralisation of power and a massive expansion of armies in Polands neighbours ( Prussia (Germany) , Russia and Austria) led to three partitions when the neighbours sliced up Poland for themselves during 1772 , 1793 and finally in 1795 there was no Polish state.

These three powerful neighbours eventually quarrelled amongs themselves leading to the 1st World War 1914-1919 when all three were defeated by the western allied powers of Britain, France and America.

A short Polish Bolshewik war followed in 1919-1921 and Poland was back on the map and the 2nd Republic was born.

Whilst Poland did not get back all the territory that it lost during the partitions it did get back some eastern lands taken in the final partition by Russia and these border lands with Russia are known as Kresy.

The Polish counties in the Kresy were Wilno, Nowogrodek, Polesie, Wolyn, Tarnapol and Stanislawow.

After World War 2 Russia claimed back all the lands that it had partitioned by 1795 and also an area that would now include the historic Polish city of Lwow.( Grey area below )

To compensate Poland for this loss it was awarded some territory from Germany in the west ( shown as Pink in map below )

Map above shows Poland as it is today ( Pink and White areas ) and as it was between the wars ( White and Grey )

The grey being Kresy.

More details at wiki : http://en.wikipedia.org/wiki/Kresy