Claim: Wladimir Klitschko reached a career peak in the 21st century.

The 21st century is the current century of the Anno Domini era , in accordance with the Gregorian calendar . It began on January 1 , 2001 and will end on December 31 , 2100 . It is the first century of the 3rd millennium . It is distinct from the time span known as the 2000s , which began on January 1 , 2000 and will end on December 31 , 2099 .