Counter Reformation
Also known as the Catholic Reformation, generally refers to a period of
Roman Catholic Church history in the 16th and 17th centuries.  The
Counter Reformation consisted of two related movements:  1) 
a defensive reaction against the Protestant
Reformation, and  2)  Catholic reform.
The Roman Catholic Church called the Council
of Trent partly as a defense against Protestantism.  It defined
Catholic doctrine on questions disputed by Protestant theologians.