Barriers are barriers to road traffic. They can be used as barriers to fences during road construction, oil pressure security barriers outside important buildings to prevent terrorist attacks, or temporary roadblocks built by demonstrators during large demonstrations. The use of roadblocks may have originated in turbulent Paris in the 16th century. Under the rule of King Henry III, the French people lived a hard life. On May 12, 1588, Duke Giss's supporters rushed to the streets to build roadblocks, historically known as the First Day of the Barricades. In the next two centuries, roadblocks in France's major social movements play an extremely important role.