Seynt Valentynes day

The Parlement of Foules (parliament of fowls, or birds) is a poem by Geoffrey Chaucer written in about 1381. It mentions Saint Valentine’s Day as a special day to find a lover:

For this was on seynt Valentynes day,
Whan every foul cometh ther to chese his make,
Of every kinde, that men thenke may;
And that so huge a noyse gan they make,
That erthe and see, and tree, and every lake
So ful was, that unnethe was ther space
For me to stonde, so ful was al the place.The Parlement of Foules (lines 309-315)

For this was on Saint Valentine’s day,
When every fowl comes there to choose his mate
Of every kind that men can think of,
And that so huge a noise did they make
That earth and sea and tree and every lake
So full was, that scarcely was there space
For me to stand, so full was all the place.

You can see the British Library’s manuscript of the poem. The language is Middle English. (See also this online dictionary.)