Brown’s premiership started well. He rescinded some of Blair’s more unpopular policies and proposed moving powers from the premiership to the House of Commons (like the power to declare war). He appointed Jacqui Smith as the first female Home Secretary. He responded well to a series of major incidents, including flooding and an attempted terrorist attack on Glasgow airport. By the late summer, he had a lead in the opinion polls.

Over September and October, there was speculation that Brown would call a snap general election to win a personal mandate. Media speculation intensified. However, on 6 October, he finally announced that there would be no early general election. Having done little to prevent the expectation that an election would be called, Brown’s decision to change course damaged his authority. His popularity declined and he would never recover a lead in the opinion polls.

In July 2008, Brown passed legislation to extend pre-trial detention for terror suspects, though the controversy around the measures would see them only narrowly pass the Commons and they were defeated in the Lords.

In late 2007, the bank Northern Rock asked for support from the Bank of England as a consequence of its exposure to international capital markets. There was a run on the bank as panicked customers withdrew their money, even though the bank’s assets were covered. In February 2008, the bank was nationalised by the government.

Northern Rock was a harbinger of the 2008 financial crisis. In late 2008, as a consequence of the bursting of the US housing bubble, markets fell as securities were revealed to be valueless. Lehman Brothers, a US investment banking firm, declared bankruptcy on 15 September, the largest filing in American history. Markets plummeted.

The British banking sector was seriously impacted by the trouble in the US. By early October, Royal Bank of Scotland and HBOS were in serious trouble. Officials feared contagion, with the collapse of these banks causing a chain reaction that would bring down the entire sector. Over the course of an exhausting weekend, Brown and Chancellor Alistair Darling put together a rescue package and five point plan to prevent disaster. In order to compel the bankers to sign up to the government’s terms, Darling told them that they must assent by midnight or their banks would open on Monday morning and they’d simply have to accept the consequences. They accepted. At 5am on Monday morning, hours before markets opened, an official woke Brown, and he approved the deal.

As a consequence, the government took stakes in HBOS, Lloyds TSB, and RBS, in return for £37 billion in capital. Ultimately, over 2007-2009, the British government spent £137 billion on bank rescue packages, preventing a sector-wide collapse. However, a heavy recession began.

In April 2009, Brown hosted the G20 summit, using it as an opportunity to engage international leaders on a global response to the crisis.

By 2009, tensions in the government emerged between Brown, who favoured spending to stimulate the economy, and Darling, who believed that budget cuts were necessary.

With Brown trailing in the opinion polls, Labour performed poorly in local elections in 2008 and was badly defeated in the 2009 European elections. As a result, Brown’s command of the Labour Party started to seem precarious, and there were several plots to replace him, though none succeeded.

In foreign policy, Brown remained close to the US, though his relationship with US President Bush was notably colder than with Blair.

In 2007, Brown signed the Lisbon Treaty, and it was ratified by Parliament the following year. Though Labour had promised a referendum on the 2005 European Constitution, Brown believed that Lisbon was sufficiently different, and therefore did not require a referendum.

Brown effectively ended Britain’s combat mission in Iraq in 2009 (with final withdrawal in 2011). British forces in Afghanistan were increased, echoing new US President Barack Obama’s ‘surge’ strategy. But the government was strongly criticised when casualties mounted in late 2009.

Brown was also passionate about the dangers of climate change. He played a key role in negotiating the Copenhagen Accord and his government passed the Climate Change Act in 2008.

In the 2010 election, Labour lost 91 seats, but Brown was able to prevent the Tories winning. Over the days that followed, he briefly tried to construct a coalition agreement with the Lib Dems, even pledging to step down by the end of the year, if his leadership was the issue that prevented a government’s formation. Ultimately, the Lib Dems chose a coalition with the Conservatives, and, when this became clear, Brown resigned on the evening of 12 May 2010.