Having heard the phrase, "faint heart never won fair lady" for the third time in very short span, I'm determined to find out its origin. Unfortunately, when I Google, I'm getting a bunch of low-quality sites — unlike our StackExchange — that only mention that it's a proverb, and give no clue as to its origin or date of first occurrence. That's what I'm wondering — is it a literary quote, passed down from some famous author into a proverb? When is the date of its first attestation? How familiar would an ordinary Briton be with this saying? (It's a chiefly British saying, right? I don't believe it's popular in the United States.)
This saying originated from a Middle English saying, round about 1545 A.D.
A coward verely neuer obteyned the loue of a faire lady. [1545 R. Taverner tr. Erasmus' Adages (ed. 2) 10]
In 1614 A.D., this was refined to become:
Faint heart neuer wonne faire Lady. [1614 W. Camden Remains concerning Britain (ed. 2) 306]
And later in 1754A.D., it was phrased in today's recognizable English:
Then, madam, we will not take your denial. ‥Have I not heard it said, that faint heart never won fair lady. [1754 Richardson Grandison I. xvi.]
Thus is the origin of this saying.
These sayings were taken out of these books.
If you do not wish to browse through all those books for these few phrases, try this site
Earliest uses of the saying, in the modern form and in print, provided by Google Books is 1672, which is earlier than what is stated by Third Idiot’s otherwise good answer. In particular, it is recorded in a French–English dictionary (1673; it translates to le couard n'aura belle amie) and an English–Latin phrasebook (1672; fortes fortunat adjuvat, whose modern translation is “fortune favours the bold”).
It is to be noted that the proverb is sometimes worded as faint heart never won fair maiden, but it appears to be a modern alteration in an effort to sound archaic. Its first recorded use in the Google Books database is in Helen Eustis’s 1946 The horizontal man.
'Faint heart never won fair lady' occurs in exactly this form in Thomas Lodge, Euphues's Golden Lagacy (usually known as 'Rosalynde', and known as the source for Shakespeare's As You Like It), said by Rosalynde (disguised as Ganymede) to Rosader. It is possibly a witticism devised for this spirited character. Written 1588, published 1590.