DEA Deutsche Erdoel AG was an international oil and gas company headquartered in Hamburg, Germany.

[5][6] DEA had stakes in oil fields in Alsace, Austria-Hungary and Romania from 1905/1906, but lost most of its foreign production when the World War I broke out.

Unlike extraction close to the surface or by means of wells, this involved the first-ever application of the complex shaft construction method, in which oil is “mined”.

[5] However, domestic oil production was not able to secure the company's survival and so DEA focused on coal mining until the early 1930s.

[7] DEA benefited from the seizure of power by the National Socialists, such as in the form of loans under the Reich Drilling Programme from 1934 onwards.

[5] Greater self-sufficiency in German's supply of raw materials had been an official goal of the National Socialist state since Adolf Hitler's Four-Year Plan Memorandum in 1936.

The company began production operations in Czechoslovakia and in Alsace by participating in consortia such as Kontinentale Öl AG, which was founded in 1941.

[citation needed] At the time, the company's business activities covered a large part of the production and supply chain: extraction, processing and utilisation of mineral oil products and their resale, acquisition of and trading in mining rights, and the manufacture of mining machinery and equipment.

[16] In 1963 an employee of DEA, Rudolf Dittrich, and his team in Wieze were instrumental in rescuing 14 miners who were trapped for many days in a collapsed coal mine in Lengede, Lower Saxony.

[15] The takeover of Deutsche Texaco by RWE AG in 1988 created RWE-DEA Aktiengesellschaft für Mineraloel und Chemie.

[28] In June, the German Federal Minister for Economic Affairs, Sigmar Gabriel, ordered an examination of the sale, which lasted for two months.

[30] In October 2014, the Financial Times reported that the British Secretary of State for Energy Edward Davey would not agree to the sale in view of the tighter sanctions imposed on Russia.

[31] The multi-billion transaction was finally closed, despite the misgivings of the British government, at the start of the first week in March 2015.