With the Roman Empire crumbling at all sides by a severely weakening economy and threats from all borders- the Huns, Slavs, Gauls and Turks, more and more capable men were required to to be recruited as soldiers and officers to protect the nation from takeover.
When Claudius II became the emperor, he felt that married men were more emotionally attached to their families, and thus, will not make good soldiers. He believed that marriage made the men weak.
So Claudius issued an edict forbidding marriage to assure quality soldiers. The Romans were in shock but dared not speak out on this edict.
Valentine saw the decree as a great injustice and took great sympathy on those denied the right to marry, so he would perform secret ceremonies. It was only a matter of time before Claudius came to know of this and had him arrested.
Asterius had a blind daughter and knowing of the miraculous powers of Valentine he requested the latter to restore the sight of his blind daughter.
The Catholic legend has it that Valentine did this through the vehicle of his strong Christian faith
The emperor tried to convert Valentine to the Roman gods but was unsuccessful in his efforts. as Valentine refused to recognize Roman Gods and even attempted to convert the emperor, knowing the consequences fully.
Claudius was angered and gave the order of execution of Valentine.
Just before his execution, Valentine asked for a pen and paper from his jailor, and signed a farewell message to her "From Your Valentine," a phrase that lived ever after that expressed great love toward her..
It wasn't emotional or sexual love expressed, but Christian love; the love of his Faith.