This global war that lasts from 1939 to 1945. The vast majority of the world's countries (including all the great powers) eventually formed two opposing military alliances during the conflict: the Allies and Axis.

A state of total war emerges, directly involving more than 100 million people from over 30 countries. The major participants put their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources.

This is also the deadliest conflict in human history, marked by 70 to 85 million fatalities, most of whom are civilians in the Soviet Union and China. It includes massacres, the Holocaust genocide, strategic bombing, premeditated death from starvation and disease, and the only use of nuclear weapons in war.

At the Potsdam Conference, following Germany's unconditional surrender on 8 May 1945, the Allies divided Germany into four military occupation zones, with France in the southwest, Britain in the northwest, the United States in the south and the Soviet Union in the east.

At the conference, these four zones are denoted 'Germany as a whole' and the four Allied Powers exercise a sovereign authority they now claim within Germany by agreeing 'in principle' to the future transfer of the former German Reich lands east of 'Germany as a whole' to Poland and the Soviet Union.

All Nazi land expansion from 1938 to 1945 is also treated as automatically invalid.

Starting with strike action by East Berlin construction workers on 16 June, this quickly turns into a widespread uprising the following day against the Democratic Republic government. More than one million people in 700 localities take part in the uprising, which is violently suppressed by tanks of the Soviet occupation forces, together with the Kasernierte Volkspolizei.

In spite of the intervention of Soviet troops, the strikes and protests are not easily brought under control and there are also related demonstrations in more than 500 towns and villages.

After the integration of West Germany into NATO in 1955, the Warsaw Pact (formally the Treaty of Friendship, Cooperation and Mutual Assistance) is signed in May 1945 as a collective defence treaty in Warsaw between the Soviet Union and seven Eastern Bloc satellite states.

The Warsaw Pact is the military complement to the Council for Mutual Economic Assistance (Comecon), the regional economic organisation for the Socialist states of Central and Eastern Europe. The Warsaw Pact also offers the Soviet Union an opportunity to control military forces in central and Eastern Europe.

On 15 June 1961, First Secretary of the Socialist Unity Party and GDR State Council chairman Walter Ulbricht states in a press conference, 'Niemand hat die Absicht, eine Mauer zu errichten!' (No one has the intention of erecting a wall). The transcript of a telephone call between Nikita Khrushchev and Ulbricht on 1 August suggests that the initiative for the construction of the Wall came from Khrushchev (Ulbricht had pushed for a border closure for some time, arguing that East Germany's existence is at stake).

At the 1961 Vienna summit, President Kennedy admits that the US will not actively oppose the building of a barrier. On 12 August 1961, the leaders of the GDR attend a garden party in Döllnsee, where Ulbricht signs the order to close the East German border and erect a wall. At midnight, the police and East German army begin to close the border and, by 13 August, the border with West Berlin is sealed.

Later, the initial barrier is built-up into the Wall proper, and the first concrete elements and large blocks were put in place on 17 August. During the construction process, the National People's Army and Combat Groups of the Working Class soldiers stand in front of the Wall with orders to shoot anyone who attempts to defect. Chain fences, smaller walls, minefields and other obstacles are installed along the length of East Germany's western border with West Germany, while a no man's land is also cleared to provide a clear line of fire at fleeing refugees during the period.

Détente (French for 'relaxation') characterises the easing of strained relations, especially in a political situation, through verbal communication. Mostly the term is used for a phase of the Cold War between 1969 and 1974 when it is the guiding policy to relax tensions between East and West, as promoted by Richard Nixon, Henry Kissinger and Leonid Brezhnev.

After Nixon leaves office, Brezhnev expands Soviet influence internationally, resulting in the Soviet invasion of Afghanistan in 1979 - the endpoint for détente.

The final act of the Conference on Security and Co-operation in Europe, the Helsinki Accords are signed in Helsinki, Finland. Thirty-five countries, including the US, Canada and all the European countries (except Albania and Andorra) sign the declaration in an attempt to improve relations between East and West.

The Helsinki Accords do not have treaty status but are seen as a significant step toward reducing Cold War tensions and as a diplomatic boost for the Soviet Union because of its clauses on the inviolability of national frontiers and respect for territorial integrity (seen by many to consolidate the USSR's territorial gains in Eastern Europe following the World War II).

President Gerald Ford reaffirms that the US non-recognition of the Baltic states (Lithuania, Latvia and Estonia) forced incorporation into the Soviet Union has not changed. The civil rights portion of the agreement provides the basis for the work of the Moscow Helsinki Group, an independent non-governmental organisation created to monitor compliance with the Accords (which evolves into the International Helsinki Federation and Human Rights Watch).

While these provisions apply to all signatories, attention focuses on their application to the Soviet Union and the Warsaw Pact. Soviet propaganda presents the Final Act as a triumph for Soviet diplomacy and Brezhnev personally, though the Helsinki Accords also become a focus for the dissident and liberal movement in Eastern Europe.

The 1979 United Kingdom general election sees the Conservative Party led by Margaret Thatcher oust the incumbent Labour government led by James Callaghan.

The Conservative campaign pledges to control inflation and curb the power of the unions, while the Labour campaign is hampered by industrial disputes and strikes during the winter of 1978-79 (known as the Winter of Discontent).

The 1979 election is the first of four consecutive election victories for the Conservative Party, which leads to a radical reshaping of British society as the country shifted to a deregulated, free-market economy.

The 1980 United States presidential election sees Republican Ronald Reagan defeat the incumbent Democrat Jimmy Carter. Due to the rise of conservatism following Reagan's victory, some consider this to be a realigning election that marks the start of the 'Reagan Era'.

During the election campaign, Reagan campaigned for increased defence spending, a supply-side economic plan and a balanced budget. His campaign is aided by Democratic dissatisfaction with Carter, the Iran hostage crisis and deflation (characterised by high unemployment and inflation).

Carter attacks Reagan as a dangerous right-wing extremist, but Reagan goes on to win the election by a landslide, taking a large majority of the electoral vote and 50.7% of the popular vote.

From its beginning, East Germany maintains a command economy similar to the economic system in the Soviet Union and other Comecon members. As part of this model, the state establishes production targets and prices and allocates resources, codifying these decisions into economic plans, with the means of production almost entirely state-owned.

East Germany has generally higher standards of living than other Eastern Bloc countries or the Soviet Union during the epoch of Soviet communism and enjoys favourable duty and tariff terms with West Germany. In the early 1970s, comprehensive long-term economic planning begins, which promotes consumer socialism to magnify the appeal of socialism by offering special consideration for the material needs of the East German working class.

Any remaining small and middle-sized private companies are nationalised in 1972, causing shortages of certain goods as these enterprises become subject to central planning and controls. However, the global rise in commodity prices in the 1970s seriously affects East Germany and a steep rise in coffee prices in 1976-77 leads to a quadrupling of the amount of hard currency needed to import coffee (leading to the 'East German coffee crisis').

After Poland goes bankrupt, the West imposes a credit boycott on Eastern Bloc countries, including East Germany. A long period of underinvestment in research and capital goods then make East German products uncompetitive on Western markets, while the East German debt-to-GDP ratio reaches 20% in 1989, a large (if manageable) level in relation to the GDR's capacity to export goods to the West to provide the hard currency needed to service its debts as the economy stagnates.

The Pan-European Picnic is a peace demonstration held on the Austrian-Hungarian border near Sopron, Hungary on 19 August 1989, the day before the Hungarian holiday commemorating Stephen I of Hungary.

Characterised as part of the revolutions of 1989 leading to the lifting of the Iron Curtain and more directly to the reunification of Germany, it is organised by the Paneuropean Union and the opposition Hungarian Democratic Forum under the sponsorship of Archduke Otto von Habsburg and Imre Pozsgay.

Following disruption in Poland and Hungary as the Eastern Bloc adjusts to the rapid weakening of Soviet control, together with associated economic and strategic pressure, the Berlin Wall opens to the West, without planning, but with hope and confusion.