Rubi,
I would argue that there are two central tenets of the importance of Queen Elizabeth's reign in the late 16th century. Firstly she cemented Protestantism and the validity of the Church of England. Queen Mary's movement to re-establish Catholicism and Papal relations could have easily reversed the relatively young British reformation. It was during the Elizabethan age that the British asserted definitive national unity behind Protestantism, paving the way for modern Christianity.
The victory over the Spanish armada is the 2nd major factor. Though the British were late to colonialism with the defeat of the Spanish, Britain would rise to colonial dominance over the next couple of centuries.
Cawthorne, N. (2009). Kings and Queens of England. New York: Arcturus Publishing.
