Eni constantly ranks among the top 100 on Fortune Global 500 list for largest companies by revenue. In 2016, the company holds the 65th place, a fall of 40 places from the previous year's 25th rank.
Eni was founded and established by law in 1953 from an existing company, Agip, which was created in 1926 with the aim to explore for oilfields, acquire and commercialize oil and derivatives. In March 1953, Enrico Mattei was nominated Eni's Chairman.
Eni originally was an acronym for the company's full title Ente Nazionale Idrocarburi. Since 1995 the meaning ceased to be relevant but the name was maintained.
In 1952 Eni chooses its own logo, the six-legged dog, an imaginary animal symbolizing the sum of a car's four wheels and the two legs of its driver.
Starting 1954 Eni holds extensive exploration rights in North Africa, signing an agreement with the Egyptian government led by Nasser while providing an active and equal role for the crude producing countries through the establishment of joint ventures.
In October 1973 after the Yom Kippur War and the embargo against the United States and the Netherlands agreed by OPEC members Arab countries, a serious oil crisis occurred, pushing Eni in need to consolidate its position in the international market by signing an agreement with Sonatrach, the Algerian state oil entity for natural gas supply.
During the mid-1970s Eni planned a major infrastructure for transporting natural gas over long distances by building a pipeline network of thousands of miles throughout Europe and the Mediterranean.
From 1995 to 1998 Eni put four share offers fully successfully, as 70% of its capital assets were sold to private shareholders.
As the price of oil collapsed in 1998 as other major companies Eni got to turn into a race through merges, international acquisitions, new explorations and the foundation of real super-companies.
Activist asset manager Knight Vinke, who owns 1% of the outstanding shares of the company, begun pressuring Eni's management to operate a spin-off of Eni's gas activities. In its opinion this would solve the undervaluation of the company and release up to 50 billion euros ($70bn) of hidden value.
In 2010 Eni achieves key production milestone in Iraqi Zubair oil field.
In February 2014, ENI discovered oil at its DRC offshore block.
Since 2012 Eni has been selling off refining and marketing assets it owned in eastern Europe in order to increase profitability. By 2013 Eni already reduced its refining capacity by 13 percent. In May 2014 Eni agreed to sell their 32.5% share in Česká rafinerská a.s. (CRC), a refining company in Czech Republic, to MOL Group of Hungary.
In June 2014 the company signed an agreement with Sasol to acquire a 40% interest in a permit to explore 82,000-km2 offshore of South Africa's east coast.
In January 2015, Eni in collaboration with Vitol Energy signed a $7 billion contract with the government of Ghana. This agreement was reached in order to produce oil and gas at Cape Three Points in the Western Region of Ghana, in an attempt to enable Ghana meet its power and energy needs.
In August 2015 Eni announced the discovery of a huge gasfield off the coast of Egypt.
In 2012 Eni reported liquids and gas production for the full year of 1,701 kboe/d, this being calculated assuming a natural gas conversion factor to barrel equivalent, updated to 5,492 cubic feet of gas equal 1 barrel of oil from July 1, 2012.
During 2012 60 new exploratory wells were drilled, as 56 were drilled in 2011 and 47 in 2010. The overall commercial success rate was 40% (40.8% net to Eni) as compared to 42% in 2011 (38.6% net to Eni) and 41% in 2010 (39% net to Eni). In 2012 351 development wells were drilled as well, as 407 in 2011 and 399 in 2010.
Gas and Power
In 2012, sales of natural gas were 95.32 bcm, down 1.44 bcm compared to 2011.
Eni operates in engineering, construction and drilling both offshore and onshore for the oil&gas industry through the subsidiary Saipem.
In April 2012, Eni in collaboration with ZEiTECS announced the world's first offshore rigless/wireline retrievable ESP system for Eni Congo.
Eni's principal subsidiaries include:
Eni Gas & Power (100% owned) – a natural gas and power company based in Belgium formed by merger of Distrigas and Nuon Belgium
versalis (fr) (100% owned) – Versalis is a chemical company that manages the production and marketing of petrochemical products such as olefines, aromatics and intermediates (base chemicals), styrenes, elastomers and polyethylene, plus in recent years a focus on green chemistry, being also able to count on a range of proprietary technologies, advanced plant facilities and a broad-based distribution network.
Saipem (43% owned) – Saipem is an oil and gas industry contractor. Saipem has contracted for engineering, oilfield services and construction both offshore and onshore through several pipelines, including Blue Stream, Greenstream, Nord Stream and South Stream. It is a subsidiary listed on the Italian Stock Exchange.
Eni UK – carries out operations in the British section of the North Sea, in the Irish Sea and off the coast of the Shetland Islands. Has been present in UK since 1964. In 2006 Eni UK's average net production of hydrocarbons was more than 141,000 boe/d.
Eni India – is expected to start drilling at a deepwater block 2, near Andaman and Nicobar Islands in Q2 of 2011 as it has received 2-year extension for the completion of drilling program. The program was delayed due to various environmental issues and scarcity of oil rigs. ENI India had won this block in 2005 and partners with ONGC and GAIL India.
In 2009, the European Commission filed formal antitrust charges against Eni. The commission believes that Eni has conspired to keep competitors from using its gas pipelines.
In 2009 again, according to the WikiLeaks cables, US ambassador Lanier told Washington that bribery allegations were made in Uganda by Eni which at the time was in competition for oil assets in the country against Tullow Oil. The bribes were taken by the newly appointed Ugandan prime minister, Amama Mbabazi. 
After corruption charges against the subsidiary Saipem, Eni's CFO Alessandro Bernini had to resign and the new CFO Massimo Mondazzi took over in December 2012.
In 2012 Eni is also included in the Carbon Performance Leadership Index and is the only FTSE MIB company to gain the triple E for Standard Ethics.
During 2012, Eni decreased CO2 emission that resulted from flaring by 10% as compared to 2011.
In 2013 Eni has been confirmed in the Dow Jones Sustainability Indices and, in the half-yearly review in March 2014, also in the FTSE4 good sustainability index.
In 2013 Eni continued its commitment to integrated reporting, preparing the Annual Report 2013 in accordance with the principles and contents of the integrated reporting (IR) framework issued by the International Integrated Reporting Council (IIRC).
Among the UN Sustainable Development Solution Network (SDSN), in 2013 Eni led the Energy For All in Sub-Saharan Africa initiative through international collaborations aimed at devising solutions to fight against energy poverty, in particular in Sub-Saharan Africa.
In 2013 Eni's commitment continued in ensuring access of local communities to energy, particularly in Sub-Saharan Africa.
In the first half of 2014 Eni achieved the start-up of the Porto Torres green chemistry plant and the Venice biorefinery.
^OGJ Editors (May 7, 2014). "Eni sheds eastern European refining assets". Oil and Gas Journal. Retrieved 20 May 2014. A series of capacity reductions in its Italian refining business over the last 3 years contributed a 13% reduction in the company's global refining capacity in 2013, according to Eni.