Nationalization means the permanent takeover of a private business by the government. Sometimes it is voluntary with full payment to the previous owners, and sometimes it is involuntary with no payment or worthless bonds.
Socialist governments nationalized industry in Britain, France and other countries after World War II. In most cases they have been privatized, that is returned to private ownership.
Temporary seizures during an emergency is not usually considered nationalization.
After World War II socialist governments came to power in several countries and set about nationalizing heavy industry, especially coal. The goal was not efficiency but to put the union leaders (who had a loud voice in socialist parties) in a position to dictate terms for the benefit of the workers, rather than the nation as a whole.
The history of British nationalization began with 1) program formation during the 1930s and World War II; 2) widespread implementation in 1945-47; 3) scaled-back activities in 1947-51; 4) stagnation and program retreat in 1951-79; 5) privatization under Margaret Thatcher's government after 1979-1990; 6) Labour acceptance of privitization under Tony Blair.
In the years 1900-18 demands for nationalization were a byword of the British Left, especially socialist organizations. The dominant influences were Fabianism and syndicalism. The interwar period saw a number of demands for nationalization and redefinitions of proposals. However, the Labour governments of 1924 and 1929-31 failed to implement nationalization.
World War II and after
The mobilization of the national economy during World War II was immediately followed by the ascendancy of the Labour Party from 1945 to 1951. The Labour platform of nationalization, planning, and creation of a welfare state was translated into the nationalization of transport, energy, and heavy industries, while other sectors of the economy were left untouched.
The postwar nationalization (1945-51) of banks, transportation, and industry fell far short of the ideals of the leftist parties. Throughout the first half of the 20th century the British workers' movements were always in the foreground of those favoring nationalization, and were able to influence the platforms of the leftist parties.
From 1951 to 1979 Britain experienced an economic decline while nationalizations increased and the welfare state was expanded. Significantly, however, a number of denationalizations also occurred during this time.
Most of Europe's coal mines passed into effective government control, with the British coal mines being nationalised under the control of the National Coal Board. The plan to nationalize the coal mines had been accepted in principle by owners and miners alike before the elections of 1945. The owners were paid £165,000,000. The government set up the National Coal Board to manage the coal mines; and it loaned it £150,000,000 to modernize the system.
The general condition of the coal industry has been unsatisfactory for many years, with poor productivity. In 1945 there were 28% more workers in the coal mines than in 1890, but the annual output was only 8% greater. Young people avoided the pits; between 1931 and 1945 the percentage of miners more than 40 years old rose from 35% to 43%, and 24,000 over 65 years old. The number of surface workers decreased between 1938 and 1945 by only 3,200, but in that same time the number of underground workers declined by 69,600, substantially altering the balance of labor in the mines. That accidents, breakdowns, and repairs in the mines were nearly twice as costly in terms of production in 1945 as they had been in 1939 was probably a by-product of the war.
Output in 1946 averaged 3,300,000 tons weekly. By summer 1946 it was clear that Britain was facing a coal shortage for the upcoming winter with stock piles 5 million tons too low. Nationalization exposed both a lack of preparation for public ownership and a failure to stabilize the industry in advance of the change. Also lacking were any significant incentives to maintain or increase coal production to meet demand.
In Eastern Europe, the Communist governments nationalized all the mines after 1945.
Co-operation on coal trading was the impetus for forming the "European Coal and Steel Community" in 1951. Integrationists like French foreign minister Robert Schuman realized that coordinating the coal and steel markets of Germany, France, Italy and the Low Countries could lead to "spillover" in other policy areas; the ECSC indeed morphed into the EEC and European Union.
Privatization has been one of the central planks of economic and industrial policy pursued by British Conservative governments since 1979, and endorsed by Tony Blair's Labour party as well.
see British Rail
The privatization on the state-owned entity British Shipbuilders (BS) was a major event. With the huge expansion of maritime industries between 1945 and 1975, British shipbuilding endured a sustained period of competitive and comparative failure, so that during the slump of the mid-1970s the industry was only saved from total failure by nationalization. British policy, however, had to act within the parameters of broader European Community (EC) legislation which was often contradictory, supporting the industry in the expectation of an upturn in demand while reducing capacity as markets remained weak. Subsidy and capacity reduction were supported by the Shipbuilding Intervention Fund (SIF), which attempted to bridge the price gap between European and Asian prices, and Counterpart Funding, designed to assist those areas where shipbuilding closed, but only on condition that no future shipbuilding be conducted. In the wake of nationalization BS established a tripartite divisional structure serving the merchant, warship, and offshore sectors. With the weak market continuing into the 1980s, both the merchant and offshore sectors were heavy loss-makers, whereas the warship sector enjoyed reasonable profits.
By 1984 privatization had been decided upon - initially, the warship yards were put up for sale - and BS had decided to pull out of the unprofitable offshore sector. Seven yards were privatized as warship yards; although this seemed (and did) meet a major criteria of injecting competitive tendering into the naval sector, the combined impact of the end of the Cold War and the inability of designated warship yards to access the SIF led to the closure of four of the yards by 1994. The merchant sector fared little better; under a tight financial regime a program of closures and dispersals was carried through between 1984 and 1989. This process was conducted against a background of criticism that the government favored closure. Moreover, there was concern that it had accepted EC Counterpart Funding as its only policy and had made little attempt to forecast either the size or nature of the market for British shipbuilding in the future. Of the 17 extant shipbuilding companies on the British mainland in 1979, only six remain open in 1996, while shipbuilding employment has fallen from 65,063 in 1979 to 12,100 in 1996. The stated aims of privatization - increasing efficiency, wider share ownership, and a reduction in public borrowing - have proven tenuous gains for British shipbuilding. 
- Ashworth, William. The History of the British Coal Industry, Volume 5, 1946-1982: The Nationalised Industry (1986)
- Foreman-Peck, James. Public and Private Ownership of British Industry, 1820-1990. (1994). 386 pp.
- Gourvish, Terry, and Mike Anson, British Rail, 1974-1997: From Integration To Privatisation, (2004) 700 pages; excerpt and text search
- Millward, Robert. "The 1940s Nationalizations in Britain: Means to an End or the Means of Production?" Economic History Review 1997 50 (2): 209-234.
- Millward, Robert and Singleton, John, eds. The Political Economy of Nationalisation in Britain, 1920-1950. (1995). 325 pp.
- Webster, Charles. The Health Services since the War. Vol. 1: Problems of Health Care: The National Health Service before 1957 (1988), on nationalizing medicine in britain
- Mark Tookey, "Three's a Crowd? Government, Owners, and Workers During the Nationalization of the British Coalmining Industry 1945-47." Twentieth Century British History 2001 12(4): 486-510. Issn: 0955-2359
- J. Gillingham, Coal, steel, and the rebirth of Europe, 1945-1955 (1991); Derek W. Urwin, The Community of Europe: A History of European Integration since 1945. (1995)
- Johnman, Lewis, "The Privatisation of British Shipbuilders" International Journal of Maritime History 1996 8(2): 1-31.