Concept:Nigeria’s Centenary Anniversary marks 100 years since the amalgamation of the Northern and Southern Protectorates.Explanation:The Centenary Anniversary was celebrated on January 1, 2014.It commemorated the amalgamation of Nigeria on January 1, 1914.This event united the Northern and Southern protectorates into one country.Former President Goodluck Jonathan launched the centenary celebrations on that date.Answer:Amalgamation of January 1st 1914.