In 1693 William Penn published his Essay on the Present and Future Peace of Europe. In this pamphlet Penn called for the establishment of a European Parliament. He argued that the voting system should be based on the demographic and economic importance of the various countries. Therefore Germany would have twelve votes whereas France, Spain, Russia and Turkey would have ten each, Italy eight and England six, an so on - a total of ninety votes in all. Penn suggested that decisions taken by the European Parliament should be enforced by a European Army.
Little interest was shown in Penn's and it was not until the end of the 18th century that the subject was revived. In 1795 the German philosopher, Immanuel Kant, wrote Philosophical Project for Perpetual Peace. He suggested that to achieve this it was necessary to create a "federation of free states".
Kant's views were supported by the English philosopher, Jeremy Bentham. In 1798 he wrote Principles of International Law where he argued that universal peace could only be obtained by first achieving European unity. He hoped that some form of European Parliament would be able to enforce the liberty of the press, free trade, the abandonment of all colonies and a reduction in the money being spent on armaments.
In 1814 the French philosopher Claude-Henri Saint-Simon published On the Reorganisation of European Society (1814). In his book Saint-Simon argued that Europe was in "critical disequilibrium" and would soon undergo reconstruction. He argued strongly for a planned economy. He suggested a framework of three chambers: one body made up of engineers and artists to propose plans, a second of scientists responsible for assessing the plans, and a third group of industrialists whose task would be that of implementing the schemes according to the interests of the whole community.
In 1851 an International Peace Congress was held in Paris. At the conference Victor Hugo called for the creation of a United States of Europe. "We say to France, to England, to Prussia, to Austria, to Spain, to Italy, to Russia, we say to them, 'A day will come when your weapons will fall from your hands, a day when war will seem absurd and be as impossible between Paris and London, St. Petersburg and Berlin, Vienna and Turin, as today it would seem impossible between Rouen and Amiens, Boston and Philadelphia."
Pierre Joseph Proudhon was also a supporter of European Unity. In Principle of Federation (1863) he argued that nationalism inevitably leads to war. To reduce the power of nationalism Proudhon called for a Federal Europe. Proudhon believed that Federalism is "the supreme guarantee of all liberty and of all law, and must, without soldiers or priests, replace both feudal and Christian society." Proudhon went on to predict that "the twentieth century will open the era of federations, or humanity will begin again a purgatory of a thousand years."
In 1900 there was a conference at the Institute of Paris on the subject of European Unity. At the conference the French lawyer, Anatole Leroy-Beaulieu, argued: "It is no longer only the dreamers and philosophers, men in love with a perhaps superhuman ideal of peace and justice, who long to realize the old Utopian idea of a European union. It is also more positive minds, concerned above all about material interests or political advantages and preoccupied with the damage which its hates and internal divisions could bring to ancient Europe."
After the First World War, the Italian industrialist, Giovanni Agnelli joined the campaign against the formation of the League of Nations. Instead he urged the establishment of "a federation of European states under a central power which governs them." He thought this would maintain peace in Europe. Agnetti also argued it would help economic growth: "Only a federal Europe will be able to give us a more economic realization of the division of labour, with the elimination of all customs barriers."
Giovanni Agnelli eventually became disillusioned with this idea and became a supporter of Benito Mussolini. Figures on the far left also embraced the idea of a a united Europe. In his book, Perspectives of World Development (1924), Leon Trotsky urged the formation of a United Socialist States of Europe in order to resist the power of American capitalism.
In 1926 Richard Coudenhove-Kalergi published his ideas for a united Europe in the Pan-Europa. The same year he established the Pan-European Union. People who joined included Albert Einstein, Thomas Mann, Sigmund Freud, Rainer Maria Rilke, Ortega y Gasset and Konrad Adenauer.
The first leading politician to propose a united Europe was the French foreign minister, Aristide Briand. In 1929 he published a memorandum where he advocated the establishment of a European Federal Union. He gained support from Edouard Herriot but the idea stimulated little interest and was not taken up by other political leaders.
In 1945 Jean Monnet was appointed as Planning Commissioner in France. In this post he became responsible for economic reconstruction. He began working on a scheme that he eventually proposed to Robert Schuman, the French Foreign Minister, in 1949. The Schuman Plan, as it became known, was the basis for the European Coal and Steel Community (ECSC) that was established in 1952. It was agreed that the six countries that signed the Treaty of Paris, Belgium, France, Italy, Luxembourg, the Netherlands and West Germany, would pool its coal and steel resources.
In 1958 the European Coal and Steel Community evolved into the European Economic Community (EEC). Under the ECC attempts were made to achieve harmonization. This included measures in areas such as indirect taxation, industrial regulation, agriculture, fisheries and monetary policies. The Common Agriculture Policy (CAP) was introduced in 1962.
Britain made attempts to join the EEC in 1963 and 1967. This ended in failure, mainly due to the opposition of President Charles De Gaulle of France. Britain, under the leadership of Edward Heath, was finally admitted in 1973. Denmark and Ireland also joined at the same time.
In 1975, the new British prime minister, Harold Wilson decided to hold a referendum on membership of the European Economic Community. Wilson allowed his Cabinet to support both the "Yes" and "No" campaigns and this led to a bitter split in the party. The Conservative Party was also divided over this issue but the British people eventually voted to remain in the EEC.
In 1979 the EEC introduced the European Monetary System (EMS). The lost-term objective of the EMS was to achieve currency union and the Exchange Rate Mechanism (ERM), a system of semi-fixed exchange rates.
Greece joined the EEC in 1981. This was followed by Portugal (1986), Spain (1986) and the former East Germany (1990). In 1993 the organization was renamed the European Union (EU). Austria, Finland and Sweden joined the EU in 1995.
In January 2002 the euro becomes the sole currency within the twelve participating Member States (Austria, Belgium, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain).