Meaning of こそすれ


Could somebody tell me the meaning of こそすれ?

I've searched it on Google, but I still don't understand what does it mean or
what function it has. Sometimes the meaning of こそすれ seems to be "to do only
something", sometimes the meaning seems to be "to never do anything", and
sometimes I simply don't know why こそすれ is used. I must say that I'm completely
lost about the usage of this word.

Besides telling the meaning, if someone could give me some example sentences
where the meaning can be fully noticed, I would be really thankful.

