Around what time period was it in the chronicles of Narnia?

Answer 1

http://en.wikipedia.org/wiki/The_Chronicles_of_Narnia#The_Narnian_universe

I don't think there is one particular time period. The books were written and published in the 1940s and 1950s, but I doubt the author meant for that to be the actual time period. Be sure to read the History section in the link above.