The Greeks gave a wreath of laurels to the victor in the Pythian games, but the victor in the Olympic games had a wreath of wild olives, the victor in the Nemean games a wreath of green parsley, and the victor in the Isthmian games a wreath of dry parsley or green pine-leaves. (See Crown.)
Laurel. The ancients believed that laurel communicated the spirit of prophecy and poetry. Hence the custom of crowning the pythoness and poets, and of putting laurel leaves under one's pillow to acquire inspiration. Another superstition was that the bay laurel was antagonistic to the stroke of lightning; but Sir Thomas Browne, in his Vulgar Errors, tells us that Vicomereatus proves from personal knowledge that this is by no means true.
Laurel, in modern times, is a symbol of victory and peace. St. Gudule, in Christian art, carries a laurel crown.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894