The South Sea Company was a British joint-stock company founded in January 1711, created as a public-private partnership to consolidate and reduce the cost of the national debt. To generate income, in 1713 the company was granted a monopoly (the Asiento de Negros) to supply enslaved Africans to the islands in the "South Seas" and South America. When the company was created, Britain was involved in the War of the Spanish Succession and Spain and Portugal controlled most of South America. There was thus no realistic prospect that trade would take place, and as it turned out, the Company never realised any significant profit from its monopoly. However, Company stock rose greatly in value as it expanded its operations dealing in government debt, and peaked in 1720 before suddenly collapsing to little above its original flotation price. The notorious economic bubble thus created, which ruined thousands of investors, became known as the South Sea Bubble.
The Bubble Act 1720 (6 Geo. 1 c. 18), which forbade the creation of joint-stock companies without royal charter, was promoted by the South Sea Company itself before its collapse.
In Great Britain, many investors were ruined by the share-price collapse, and as a result, the national economy diminished substantially. The founders of the scheme engaged in insider trading, by using their advance knowledge of the timings of national debt consolidations to make large profits from purchasing debt in advance. Huge bribes were given to politicians to support the acts of Parliament necessary for the scheme. Company money was used to deal in its own shares, and selected individuals purchasing shares were given cash loans backed by those same shares to spend on purchasing more shares. The expectation of profits from trade with South America was talked up to encourage the public to purchase shares, but the bubble prices reached far beyond what the actual profits of the business (namely the slave trade) could justify.
A parliamentary inquiry was held after the bursting of the bubble to discover its causes. A number of politicians were disgraced, and people found to have profited unlawfully from the company had personal assets confiscated proportionate to their gains (most had already been rich and remained so). Finally, the company was restructured and continued to operate for more than a century after the Bubble. The headquarters were in Threadneedle Street at the centre of the City of London, the financial district of the capital. At the time of these events, the Bank of England was also a private company dealing in national debt, and the crash of its rival confirmed its position as banker to the British government.
When in August 1710 Robert Harley was appointed Chancellor of the Exchequer, the government had already become reliant on the Bank of England, a privately owned company chartered 16 years previously, which had obtained a monopoly as the lender to the government. The government had become dissatisfied with the service it was receiving and Harley was actively seeking new ways to improve the national finances.
A new parliament met in November 1710 resolved to attend to the national finances, which were suffering from the pressures of two simultaneous wars: the War of the Spanish Succession with France, which ended in 1713, and the Great Northern War, which was not to end until 1721. Harley came prepared, with detailed accounts describing the situation of the national debt, which was customarily a piecemeal arrangement, with each government department borrowing independently as the need arose. He released the information steadily, continually adding new reports of debts incurred and scandalous expenditure, until in January 1711 the House of Commons agreed to appoint a committee to investigate the entire debt. The committee included Harley himself, the two Auditors of the Imprests (whose task was to investigate government spending), Edward Harley (the Chancellor's brother), Paul Foley (the Chancellor's brother-in-law), the Secretary of the Treasury, William Lowndes (who had had significant responsibility for reminting the entire debased British coinage in 1696) and John Aislabie (who represented the October Club, a group of about 200 MPs who had agreed to vote together).
Harley's first concern was to find £300,000 for the next quarter's payroll for the British army operating on the Continent under the Duke of Marlborough. This funding was provided by a private consortium of Edward Gibbon (grandfather of the historian), George Caswall, and Hoare's Bank. The Bank of England had been operating a lottery on behalf of the government, but in 1710 this had produced less revenue than expected and another begun in 1711 was also performing poorly; Harley granted the authority to sell tickets to John Blunt, a director of the Hollow Sword Blade Company, which despite its name was an unofficial bank. Sales commenced on 3 March 1711 and tickets had completely sold out by 7 March, making it the first truly successful English state lottery.
The success was shortly followed by another larger lottery, "The Two Million Adventure" or "The Classis", with tickets costing £100, with a top prize of £20,000 and every ticket winning a prize of at least £10. Although prizes were advertised by their total value, they were in fact paid out by instalments in the form of a fixed annuity over a period of years, so that the government effectively held the prize money as borrowings until the whole value had been paid out to the winners. Marketing was handled by members of the Sword Blade syndicate, Gibbon selling £200,000 of tickets and earning £4,500 commission, and Blunt selling £993,000. Charles Blunt (a relative) was made Paymaster of the lottery with expenses of £5,000.
The national debt investigation concluded that a total of £9 million was owed by the government, with no specifically allocated income to pay it off. Robert Harley and John Blunt had jointly devised a scheme to consolidate this debt in much the same way that the Bank of England had consolidated previous debts, although the Bank still held the monopoly for operating as a bank. All holders of the debt (creditors) would be required to surrender it to a new company formed for the purpose, the South Sea Company, which in return would issue them shares in itself to the same nominal value. The government would make an annual payment to the Company of £568,279, equating to 6% interest plus expenses, which would then be redistributed to the shareholders as a dividend. The company was also granted a monopoly to trade with South America, a potentially lucrative enterprise, but one controlled by Spain – with which Britain was at war.
At that time, when the continent of America was being explored and colonised, Europeans applied the term "South Seas" only to South America and surrounding waters. The concession both held out the potential for future profits and encouraged a desire for an end to the war, necessary if any profits were to be made. The original suggestion for the South Sea scheme came from William Paterson, one of the founders of the Bank of England and of the financially disastrous Darien Scheme.
Harley was rewarded for delivering the scheme by being created Earl of Oxford on 23 May 1711 and was promoted to Lord High Treasurer. With a more secure position, he began secret peace negotiations with France.
The scheme to thus consolidate all government debt and to manage it better in the future held out the prospect of all existing creditors being repaid the full nominal value of their loans, which at the time before the scheme was publicised were valued at a discounted rate of £55 per £100 nominal value, as the lotteries were discredited. The government's ability to repay in full was widely doubted. Thus bonds representing the debt intended to be consolidated under the scheme were available for purchase on the open market at a price that allowed anyone with advance knowledge to buy and resell in the immediate future at a high profit, for as soon as the scheme became publicised the bonds would once again be worth at least their nominal value, as repayment was now more certain a prospect. This anticipation of gain made it possible for Harley to bring further financial supporters into the scheme, such as James Bateman and Theodore Janssen.