Empires rise, and empires fall. By the time of Claudius II (emporer, AD268-270), the Roman Empire was in serious decline. The whole culture was built on slavery. As long as there were more people to conquer (largely by conscipting already-conquered men into the conquerors army), the supply of slaves - and therefore the way of life - was secured. But once there was no-one else to conquer...the Romans were left with a lot of oppressed people groups, all intent on regaining their freedom; all armed and trained in the art of warfare by the Romans themselves (think: the USA arming Osama bin Laden to fight the Russians, and Saddan Hussein to fight Iran); and no fresh source of soldiers to resist them.
It would still take another 150-or-so years before The End arrived, but Claudius II had problems (in the shape of Goths and Jutes to the north, and Palmyrans to the east, if anyone is interested). And opinions. In Claudius II's opinion, single men made better soldiers - as married men did not want to leave their wives and children. So Claudius II made getting engaged and married illegal for his citizens.
A young priest, Valentine, opposed this edict. He continued to marry couples, in secret; until he was caught; and ultimately executed on 14th February, (approx.) AD270. Valentine believed that there was a higher authority than the poltical rulers of the day, to whom he was answerable, and with whom he must side whenever conflicts of interest arose. Even if it cost him his life - as he knew it would were he to be discovered. (About fifty years later, for better and for worse, his faith became the "official" religion of the Empire.)
Today is Saint Valentine's Day, a day for lovers to mark their love. Buried beneath the commercialisation - and layers of tradition beneath that - Valentine challenges our notions of love: for, "Greater love has no one than this, that he lay down his life for his friends" (John 15:13)