Background
After France was liberated from Nazi control in 1944, a Provisional Government was set up to restore France and to create a new constitution, since the one from the Third Republic was horridly flawed. The famous and beloved Charles de Gaulle was in charge of the temporary government, and a constitution was finally passed by a narrow margin in 1946. This new constitution of the Fourth Republic was eerily similar to the constitution of the Third Republic with few minor changes. This basically meant that things would have different names, but all the problems still existed. These problems were: instability, ineffectiveness, ceremonial president (much like the royal family of Great Britain in this age), a premiere and cabinet (executive branch) that was horridly susceptible to the will of the legislature (now called the National Assembly, as it was before the Third Republic), and no real way of controlling the economy or shifting social problems.
Good things of the Fourth Republic
De Gaulle resigned quickly after the formation of the Fourth Republic, but occasionally returned as the leader of a movement called Rally of French People which faded into the background by 1953. Surprisingly enough, leftist radicals took over after de Gaulle's departure. The strongest parties were the communists and the socialists. The communist party alone received one fourth the electorate’s vote, a great deal when there are a couple dozen or so political parties. The communists were denied key cabinet positions, but to appease them, they were given some power over recovery of the economy.
Instability and public indifference grew, and the government was weakened from within over time. There was a brief change in the decline of the government as a reformist actually was in charge of the government for more than a few months; Pierre Mendés-France greatly increased public awareness and political activity from 1954 to 1955.
The Fourth Republic had no sweeping social changes that the Third had, but it did stabilize and strengthen France's National Economy. Many industries were Nationalized, including coal mining, electrical power, and most financial institutions. Social security was expanded and the Monnet Plan, drafted by Jean Monnet, was used to modernize and enlarge France's modern economic base (mostly using American money from the Marshall plan). Industrial output was at 150% of what it was pre-WWII, and growth was a constant five percent in the postwar years.
The fall of the Fourth
The downfall of the Fourth Republic was in both domestic and international politics while trying desperately to maintain the French Empire of the Imperialistic era before WWI. The domestic affairs weren't really what felled the Fourth Republic, but they helped a great deal; abuse of public finances, massive tax evasion, inflation, and many political and labor strikes (mostly organized by the communists) all doomed the Republic.
Many scholars agree that the Vietnam War began in 1954 when the French were battling revolutionary forces in Vietnam. The French were almost constantly at war from 1939 to 1962. In 1954, only a few months after French withdrawal from Indochina, an independence war broke out in Algeria. The war dragged on for four years before the French decided to withdraw. Not accepting this, the French military forces and settlers of Algiers staged a coup in 1958. The government of France brought in the one man who could save France while keeping Algeria under French control, Charles de Gaulle. De Gaulle was given emergency powers for six months. One of the powers he was granted was to authorize the preparation of a new constitution, which he quickly did with an overwhelming popular majority, thus bringing France's Fifth Republic into existence.
Sources :
Palmer, R.R. and Joel Colton. A History of the Modern World. 6th Edition. New York. 1950.
A note on Charles de Gaulle’s name – as far as I can remember, Charles de Gaulle’s last name is “de Gaulle.” Indeed, in my source, in the middle of a sentence it refers to him as “de Gaulle.” A French online source, http://charles-de-gaulle.org lists him as both “De Gaulle” and “de Gaulle.”