You use the word prior when speaking to an event, like; prior to an event, it means this happened before a certain event, or before something happened. Say there was a crime, and people were talking about how this happened, and what happened prior to this event.
The bubonic plague or black death
Gunpowder was invented in china around 800ad and leaked out at 1200 ad to europe
something that has happened before
D-Day
world war 1 Chuck Norris got ahold of a kid's water gun and took over the world
dokach
Most Horrific Event in the 1500sThis is the century in which the black plague killed half of the population in Europe. This happened in the years 1548 - 1553.
They are called chronological order. An event that happened in 2001 would come before an event that happened in 2002.
The CRUSADES eventually had this impact.
John Juanda won the 2010 World Series of Poker Europe main event.
World War I (1914-1918) took place before the Vietnam War (1955-1975).