What year did the fourteenth century start?

The first year of the 14th century was 1301 and the last year of the 14th century was 1400.

All centuries begin on the year whose leading digits are the number one less than the century and whose last digit is 1 and end on the year whose leading digits are the number of the century and whose last two digits are 00.

1. year 1 to 100, 1st century
2. year 101 to 200, 2nd century
3. year 201 to 300, 3rd century
4. etc.

This is true for both AD and BC, there is no year "0" between them.