Barter: It dates back to the beginning of human kind, people used to exchange what they had by what they hadn’t. And this provided mutual advantage for both sides.

9,000 -- 6,000 BC:

Cattle: due to the disadvantages of barter, like not providing a value for things as you may exchange a pound of meat for a pound of bananas, just because you don’t have banana. Cattle was used as the first medium in exchanging goods, it was the primitive form of money. It gave the utility to value things and not to lose what you got for what you need.

1,200 BC:

Cowrie Shells: The cowrie, which is the shell of mollusc, was first used in china. It has been used for a long time in different places like in some places of Africa where it has been used till the middle of the 20th century.  

1,000 BC:

First Metal Money and Coins: at the end of the Stone Age, china made bronze and silver imitations of cowrie shells, also some metal tools were used as money like knives and spades.These primitive forms of money developed into the coins we know nowadays.

500 BC:

Modern Coinage: from lumps of silver the first form of coins was done, it took the familiar form with gods and emperors to mark them. It appeared first in Lydia and the techniques were quickly copied to Greek, Macedonian, Persian and Romans. It was made of gold, silver, bronze which had a great value, it was unlike the Chinese coins which was made of base metals. 

118 BC:

Leather Money: a Step towards paper money. In china, One-foot square pieces of white deerskin edged in vivid colours were exchanged for goods.

800 - 900 AD:

The Nose: The phrase "To pay through the nose" comes from Danes in Ireland, who slit the noses of those who were remiss in paying the Danish poll tax.

806 AD:

Paper Currency: From the ninth century to the fifteenth century A.D., in China, the first actual paper currency was used as money. Through this period the amount of currency skyrocketed causing severe inflation. Unfortunately, in 1455 the use of the currency vanished from China. European civilization still would not have paper currency for many years.

1816:

The Gold Standard: Gold was officially made the standard of value in England in 1816. At this time, guidelines were made to allow for a non-inflationary production of standard banknotes which represented a certain amount of gold. Banknotes had been used in England and Europe for several hundred years before this time, but their worth had never been tied directly to gold. In the United States, the Gold Standard Act was officially enacted in 1900, which helped lead to the establishment of a central bank.

1930:

End of the Gold Standard: The massive Depression of the 1930's, felt worldwide, marked the beginning of the end of the gold standard. In the United States, the gold standard was revised and the price of gold was devalued. This was the first step in ending the relationship altogether. The British and international gold standards soon ended as well, and the complexities of international monetary regulation began.

1947

Trade liberalisation: with the Second World War just ended, countries met in Geneva to try to give an early boost to trade liberalisation. Some 23 countries decided to negotiate to reduce customs tariffs. On October 30, 1947, they signed the General Agreement on Tariffs and Trade (GATT).

The first round of trade negotiations (1947-1948)

Resulted in 45,000 tariff concessions affecting one fifth of total world trade. In November, delegates from 56 countries met in Havana to start negotiating the charter of a proposed International Trade Organization. It was signed in March 1948 but governments did not commit themselves to ratify it, leaving the GATT as the only international instrument governing world trade. The GATT entered into force on January 1.

The second GATT round of trade talks (1949)

Was held at Annecy in France in 1949 where countries exchanged some 5,000 tariff concessions. The southern English seaside town of Torquay hosted the third GATT round in 1950 during which countries exchanged some 8,700 tariff concessions, cutting 1948 tariff levels by 25%.

1955-56

The next trade round completed in May 1956 produced some $2.5 billion worth of tariff reductions.

1960-62

Fifth GATT round named in honour of US Under Secretary of State Douglas Dillon who proposed the negotiations. It yielded tariff concessions worth $4.9 billion of world trade and involved negotiations related to the creation of the European Economic Community

1964-67

The Kennedy Round, named in honour of the late US President, achieved tariff cuts worth $40 billion of world trade.

1973-79

The seventh round, launched in Tokyo, Japan, saw GATT reach agreement to start reducing not only tariffs but trade barriers as well, such as subsidies and import licensing. Tariff reductions worth more than $300 billion achieved.

1986-93

GATT trade ministers launched the Uruguay Round in Punta Del Este, Uruguay, embarking on the most ambitious and far-reaching trade round so far.

1994

Trade ministers meet for the final time under GATT auspices at Marrakesh, Morocco to establish the World Trade Organization and sign other agreements.

1995

The World Trade Organization is created in Geneva. The main differences between the WTO and the GATT are that GATT was a provisional legal agreement, whereas the WTO is an organization with permanent agreements. The WTO has members, GATT had only contracting parties. GATT dealt only with trade in goods, the WTO covers services and intellectual property as well.