Big Ben

After the old Palace of Westminster was largely destroyed by fire on 16 October 1834, Charles Barry designed a new neo-Gothic palace and turned to Augustus Pugin for the Clock Tower, which resembled Pugin's earlier designs, including one for Scarisbrick Hall, a country house in Lancashire. Construction began on 28 September 1843, carried out by contractors Thomas Grissell and Morton Peto. It was Pugin's last design before his descent into mental illness and death in 1852; on handing over the finished drawings, Pugin wrote that he had "never worked so hard" in his life.

The tower was completed in 1859, standing 316 feet (96 m) tall on a square base 40 feet (12 m) to a side, its brick core clad in sand-coloured Anston limestone from South Yorkshire and topped by a spire of cast-iron roof tiles. Its foundations rest on a bed of gravel over London Clay, leaving the tower leaning slightly to the north-west.

The original hour bell, a 16-ton casting, was made on 6 August 1856 in Stockton-on-Tees by John Warner & Sons; it is thought to have been intended for the name "Victoria", but an MP suggested the nickname "Big Ben" during a parliamentary debate, a remark not recorded in Hansard. Late-1850s newspapers favoured Sir Benjamin Hall, the Minister of Works who oversaw its installation, as the source, though the boxer Ben Caunt, also nicknamed "Big Ben", has been proposed as an alternative. Mounted for testing in New Palace Yard, the bell cracked beyond repair before the tower was finished.

A replacement was cast on 10 April 1858 at the Whitechapel Bell Foundry, weighing 13.5 tons. It was hauled to the tower by sixteen horses through cheering crowds, then winched 200 feet up to the belfry over 18 hours. The new bell first chimed on 11 July 1859, but cracked again within months; the foundry's manager, George Mears, blamed horologist Edmund Beckett Denison for striking it with a hammer more than twice the specified weight. Silenced for three years, its hours struck on a quarter bell instead, it was repaired by chipping a piece of metal from around the crack and turning the bell an eighth-turn so the hammer struck a different spot. It has sounded with an altered tone, the crack unrepaired, ever since.

During the First World War the bells were silenced and the clock faces left unlit at night for two years, to deny attacking German Zeppelins a landmark; the bells rang again at 11:00 am on 11 November 1918, marking the war's end. The faces went dark again from September 1939, this time to avoid guiding Luftwaffe bombers, though the bells continued to ring.

On the night of 10–11 May 1941, near the close of the Blitz, a German raid — struck either by a small bomb or a British anti-aircraft shell — damaged two of the clock's dials and sections of the tower's stepped roof, and destroyed the adjoining Commons chamber. Stonework and ironwork were damaged and the glass of the south dial shattered. The clock ran accurately and chimed throughout the Blitz.

The tower carried the plain name Clock Tower for most of its history — Victorian journalists more often called it St Stephen's Tower, after the hall where MPs had once sat. On 2 June 2012 the House of Commons voted to rename it Elizabeth Tower for Queen Elizabeth II's Diamond Jubilee, echoing the earlier renaming of the palace's west tower as Victoria Tower for Queen Victoria's own Diamond Jubilee. The Commons confirmed the change on 26 June, and prime minister David Cameron announced it on 12 September 2012, when Speaker John Bercow unveiled a commemorative plaque on Speaker's Green.

It has been part of a Grade I listed building since 1970 and, with the rest of the Palace of Westminster, was designated a UNESCO World Heritage Site in 1987.

On 21 August 2017 the chimes fell silent for four years of conservation work, adopted to protect the hearing of workers on the tower. The estimated cost, originally around £29 million, rose to about £69 million, and then, after a 2020 inspection found the tower had suffered greater damage from the 1941 bombing than previously known, alongside asbestos and lead paint, to nearly £80 million. Restorers stripped away black paint applied in the 1930s to hide pollution stains and returned the clock face frames to their original Prussian blue, regilding the dials and replacing the Victorian glass panes with faithful reproductions. The tower re-emerged from its scaffolding in December 2021, and in September 2025 the restoration was shortlisted for the Stirling Prize.