Foules: How Romantic!

The first recorded association of Valentine's Day with romantic love is in Parlement of Foules (1382) by Geoffrey Chaucer. The poem was written to honor the first anniversary of the engagement of King Richard II of England to Anne of Bohemia. A treaty of marriage was signed on May 2, 1381. When they were married eight months later, he was 13 or 14; she was 14.

For this was on seynt Volantynys day
Whan euery bryd comyth there to chese [choose] his make [mate].

From wikipedia.com