quattrocento (n.)

"the 15th century as a period in art and architecture," 1847, from Italian quattrocento, literally "four hundred," short for mille quattrocento "one thousand four hundred," in reference to a period beginning in "1400;" see four + hundred.

The Italian pattern (also in trecento, cinquecento) is a stumbling-block for those accustomed to the English pattern of naming the centuries ordinally so that each contains only one year of the number that names it. Trecento means literally "three hundred," but stands for "the 1300s," which we call the 14th century.