http://novaonline.nvcc.edu/eli/spd130et/medieval.htm
This site talks about the history of Medieval theatre after the fall of Rome. It goes into detail about the power of the Church with Liturgical Drama, as well as drama outside of the church. The site talks about the staging, and also gives examples of plays written during the Medieval times. The site is full of useful information, but could perhaps be expanded on. Nonetheless, one could still find a lot of useful information about the history of Medieval theatre.