Why was valentine's day created/ how?

Valentines Day has something to do with a guy named St. Valentine I think?

Explanation:

I heard it sometime in my life.

1.the population change is near or at replacement level.

4. the birth and death rates are balanced.

6. sweden is most likely a developed country.

the virginia plan called for three branches of government and two houses of congress. representation in each house would be determined by population. the new jersey plan called for three branches of government and a single house of congress. each state would have an equal vote.