High Quality Content by WIKIPEDIA articles! This article is about changing canons of Renaissance English poetry (i.e. in the 16th and early 17th century). While the canon has always been in some form of flux, it is only towards the late 20th century that concerted efforts were made to challenge the canon and the very concept of a canon. Questions that once did not even have to be made, such as where to put the limitations of periods, what geographical areas to include, what genres to include, what writers and what kinds of writers to include, are now central to writers of histories, anthology editors, curriculum designers, and individual teachers and learners. For example the customary exclusion of women writers has been successfully challenged over the last twenty years.