Geoffrey Chaucer -1382
The first recorded association of Valentine’s Day with Romantic Love is in Parlement of Foules where Geoffrey Chaucer is believed to have invented the lore that birds choose their mates on Valentine’s Day…
Chaucer wrote:
“For this was on seynt Volantynys day, Whan euery bryd comyth there to chese his make.”
[“For this was Saint Valentine’s Day, when every bird cometh there to choose his mate.”]
This poem was written to honor the first anniversary of the engagement of King Richard II of England to Anne of Bohemia. A treaty providing for a marriage was signed on May 2, 1381. (When they were married eight months later, they were each only 15 years old).
From Wikipedia.