Emperor Claudius II decided to outlaw marriage so that young men can flair well in the battle field, as people who are married do not. St. Valentine raised his voice to oppose Claudius II and he helped many couples to get married in secrecy.
Claudius II came to know about his rebel and St. Valentine was thrown

The other legend talks about St. Valentine’s love for the jailors daughter whom he met when he was imprisoned.
She was blind and he cured her and she used to meet him secretly.
Before St. Valentine was assassinated, he wrote a letter to her signed, as ‘From Your Valentine’ and these last words are today the most beautiful expression on Valentine’s Day gifts.
The cupid also shares its part in the Valentine’s Day tantrum as being the legendry son of goddess of love, this naughty little kid is held responsible for hurting the young hearts with his love stuck arrows and the person falls in love.