Question

Why would the rulers of England include so many lions on the Coat of Arms?

Answer 1

Well, what is the Lion a symbol of?

Answer 2

bravery, strength, ferocity, & valour ..

Answer 3

Which is a good reason to choose one of them. The royals were supposed to symbolize those aspects of the lion. However, the reason why they chose three is actually a little different. See here:

http://www.britroyals.com/arms.htm

This covers much of the heraldry involved and if you search for lions you can find a reference to the three.