|Photo credit: Jean-Marc Ayrault|
Politician Alain Poher served twice as intermediary president since the start of the Fifth Republic in October 1958, stepping in after Charles de Gaulle resigned in April 1969 and then again after Georges Pompidou died in office in April 1974.
Since the early 19th century, France has had more than a handful of government systems, from republics to empires to constitutional monarchies.
Under the current republican system, each time a new constitution is drafted and signed into law, a new republic is also created (fifth constitution = fifth republic).
French presidents currently serve five-year terms. The next presidential elections will be held in 2017.
If you're interested, Wikipedia will give you more information about the French Fifth Republic here.