The Polish resistance movement in World War II was*
arguably the largest underground resistance in *
Nazi-occupied Europe. *
*
The main organization was the Armia Krajowa (AK)*
- Home Army, loyal to the government in exile*
in London, formed in 1942 from other organizations.*
It counted up to 400,000. The mainstream AK was the*
military arm of the Polish Underground State,*
and eventually incorporated most of other*
organizations.*
*
The second large organization was Bataliony*
Chlopskie (BCh) - Peasants' Battalions, formed by *
more leftist agrarian political party, also loyal to*
the government in exile. It counted up to 160,000.*
*
There were several other lesser organizations, some*
of them lasting from 1939.*
*
Behind the mainstream were nationalist NSZ, Jewish*
ZOB, communist GL/AL, tretaed separately.* 
*
_____________[description by PIBWL]*