Otto Frisch and Rudolf Peierls, working at the University of Birmingham in the UK, considered the possibility of fast fission in uranium-235. Their memorandum was submitted to the Committee on the Scientific Survey of Air Defence.

Fission had been discovered in Germany almost two years before and since the Spring of 1940 they had been conducting uranium research.

In March 1941 a report was produced by the MAUD Committee describing the importance of fast fission for bomb design. This was sent to the Uranium Committee in the USA.

On 15 July 1941, the MAUD Committee approved its two final reports and disbanded. One report was on the “Use of Uranium for a bomb”; the other was the “Use of Uranium as a source of power”. British nuclear weapon research begins under codename Tube Alloys.

In October 1941, the final report draft was presented to President Franklin D Roosevelt who ordered the National Academy of Sciences to support a Bomb Project. The led to the creation of the US Manhattan Project.

The Quebec Agreement between the UK and US is signed by Winston Churchill and Franklin D Roosevelt in Canada. The UK joins the US Manhattan Project.

A secret laboratory opens in Los Alamos, New Mexico to support the work of the Manhattan Project. British scientists and engineers, including Otto Frisch, Rudolf Peierls and Dr William Penney, eventually join the team in the US.

Close to the end of the Second World War, atomic bombs were used against Japan. This was the first and only time that nuclear weapons have been used in warfare.

US Atomic Energy Act (McMahon Act) excludes all countries including UK from nuclear collaboration with the US. Chiefs of Staff report on UK’s atomic bomb requirements. William Penney appointed Chief Superintendent Armament Research.

UK Cabinet Committee, under Prime Minister Clement Attlee authorises the development of nuclear weapons. The High Explosives Research division, led by Dr William Penney, established at Fort Halstead, Kent. The team at Fort Halstead went on to develop Britain’s first atomic bomb.

RAF Aldermaston, originally a wartime airfield in Berkshire becomes the site for the UK’s Atomic Programme. The first scientific staff arrive a year later

Aldermaston site is officially named Atomic Weapons Research Establishment (AWRE).

The first UK nuclear device successfully detonated. Known as Operation Hurricane, this test was led by Dr. Penney.

Dr. William Penney awarded a knighthood.

First British prototype, Blue Danube is delivered to the RAF.

Totem nuclear tests takes place in EMU Fields, Australia.

Dr William Penny is appointed director of AWRE

Ministry of Supply transfers responsibility of all atomic matters to the United Kingdom Atomic Energy Agency (UKAEA), which AWRE Aldermaston becomes part of on 1st January 1955.

ROF Burghfield enters nuclear weapons programme.

AWRE takes over Foulness and Orford Ness.

UK decision to develop hydrogen bomb announced.

First computer – Ferranti Mk 1* - installed at Aldermaston.

RAF V-class bombers enter service in UK. The Vulcan and Victor were armed with British built bombs: Red Beard, Violet Club and Yellow Sun.

The fissile material processing building at AWRE becomes operational.

UK carries out last atmospheric test, Grapple Z, at Christmas Island.

A moratorium on atmospheric nuclear weapons testing between UK, US and USSR announced.

AWRE scientists participate in the first Comprehensive Test Ban Treaty (CTBT) negotiations in Geneva

Violet Club missile enters service and is withdrawn the following year.

UK/US Mutual Defence Agreement nuclear co-operation agreed.

Red Beard enters service.

ROF Cardiff starts work on nuclear warhead programme. Purpose built warhead assembly facilities completed at ROF Burghfield.

Yellow Sun MK2 goes into service

Blacknest was incorporated into AWRE providing seismological data and assessments to UK Government for research and development, . This is a cornerstone of the Comprehensive Test Ban Treaty. The scientists based at Blacknest make important contributions in developing verifications techniques and supporting nuclear non-proliferation and arms controls treaties.

UK begins underground testing at Nevada test site. Nassau Agreement allows UK to purchase Polaris system from the US.

Partial Test Ban Treaty ends atmospheric testing. UK participates in a programme to monitor compliance with the Partial Test Ban Treaty.

Polaris Sales Agreement between the UK and the US for the Polaris missile system to be provided to the UK to maintain its independent nuclear deterrent.

Moratorium on underground nuclear test imposed

Science & Technology Act allows AWRE to diversify.

WE177B free fall bomb goes into service

First UK Polaris submarine HMS Resolution operational Underground testing marks a new era

Nuclear Non-Proliferation Treaty opened for signature. The Treaty aims to prevent the spread of nuclear weapons and weapons technology. The UK, along with the US and the Russian Federation, was one of the first nations to sign the Treaty.

Nuclear Proliferation Treaty entered into force. A total of 190 states have now joined the Treaty.

Blue Steel withdrawn from service. Red Beard and Yellow Sun Mk2 withdrawn from service two years later

UK starts Chevaline programme.

AWRE transferred to the Ministry of Defence.

Fallon Test takes place – first joint UK/US testing after a nine year break.

AWRE participates in UN Conference on disarmament (continues to 1994)

AWRE provides technical advice on detection of underground tests in US, UK and USSR trilateral negotiations.

UK Government authorises work to begin on Polaris replacement.

Pochin report recommends improved radiation protection standards which are now used in Europe and in many other parts of the world.

AWRE Helen Laser facility opened by HM the Queen.

First CRAY supercomputer installed.

First Chevaline warheads enter the stockpile. UK Government announces that Trident will replace Chevaline.

Whole body monitor opened by Sir E. Pochin

First submarine patrol with Chevaline upgrade. Polaris Sales Agreement updated to provide the Trident missile system to the UK

AWRE becomes the Atomic Weapons Establishment. ROF Burghfield and ROF Cardiff come under AWE management.

UK government announces that AWE is to be "contractorised".

Hunting- BRAE Ltd awarded phase 1 management contract for AWE.

UK’s final underground test, Bristol, takes place at the Nevada test site.

Lord William Penney dies.

AWE Bill receives Royal Assent, paving way for full contractorisation.

Hunting Brae Ltd awarded Phase 2 of management contract.

AWE receives ISO9001 quality accreditation.

First meeting of Aldermaston and Burghfield Local Liaison Committee

First Trident submarine – HMS Vanguard – enters service.

UK Government announces intention to licence AWE under the Nuclear Installations Act

CTBT negotiations begin in Geneva. AWE provides advice on verification and on-site inspection

Comprehensive Test Ban Treaty signed by UK, US and 90 non-nuclear states.

Chevaline withdrawn from service.

Nuclear Installations Inspectorate (now known as the Office for Nuclear Regulation) grants site licences for Aldermaston and Burghfield.

AWE Cardiff closes and AWE withdraws from Foulness.

AWE scientists participate in CTBT Preparatory Commission

WE177 withdrawn from service Trident warhead enters full service.

Plutonium facility at Aldermaston fully operational.

New explosives analysis facility opened at Aldermaston.

Creation of William Penney fellowships.

UK ratifies the CTBT.

British Government announces AWE Management Limited (BNFL, Lockheed Martin and Serco) to take over running AWE.

AWE transports first shipment of weapons grade plutonium to storage under International Atomic Energy Agency (IAEA) safeguards.

AWE Management Limited sign a single 25 year contract for the management and operations of AWE plc.

50th Anniversary of opening of AWRE Aldermaston.

Support for weapons convoys moved from the RAF to AWE.

AWE achieves ISO 14001 for environmental management standards of excellence.

AWE’s training scheme granted accreditation by the Royal Society of Chemistry and was re-accredited by the Institution of Mechanical Engineers and the Institution of Electrical Engineers.

Peter Marshall OBE of AWE Blacknest appointed a Companion to the Most Distinguished Order of St Michael and St George (CMG) in the Queen’s New Year’s Honours List. David Youngs of the design physics department was awarded the MBE.

In June, Mike Dunning, head of AWE’s craft and technical training, was recognised in the Queen’s Birthday Honours through the award of an MBE.

AWE is winner of RoSPA National Defence Sector Award and The Astor Trophy.

Prince Andrew visits AWE to celebrate 25th anniversary of Helen laser facility.

Work begins with the MOD on plans for a revolutionary long and short pulse replacement laser facility.

AWE’s Radionuclide Laboratory became only the fifth laboratory in the world to be certified by the CTBT Organisation in Vienna.

Recognised by RoSPA for the fourth consecutive year. ISO 9001:2000 accreditation for quality management and BS 7799 for information security.

The Secretary of State for Defence announced the programme of investment in new buildings, facilities and employees to ensure the existing Trident warhead can be maintained throughout its intended in-service life.

Government White Paper on ‘The Future of the United Kingdom’s Nuclear Deterrent’ setting out the intention to maintain the UK nuclear deterrent by procuring a new generation of ballistic missile-carrying submarines and by extending the life of the Trident D5 missile.

Award for Best Large Employer of apprentices by Learning Skills Council and ranked 24th in a review of ‘Britain’s Top 100 Employers’.

UK Parliament endorses commitment to maintain minimal deterrent beyond life of existing system.

Building work is nearing completion of the replacement laser facility, Orion. The new accommodation buildings, known as Gemini, are also underway.

Jacobs Engineering Group acquires BNFL share of AWE Management Limited.

Planning permission received for a replacement high explosives fabrication facility at Aldermaston and for a conventional manufacturing facility at Burghfield. Approval also received for the construction of a replacement warhead assembly and disassembly facility at Burghfield.

AWE Apprentice Academy in top 2% of adult learning providers in the UK and awarded Ofsted Grade 1 status.

Orion Laser facility construction completed and first target shots fired from the laser.

Willow and Blackthorn super computers give AWE 215 Teraflops of processing capability with upgrade to 450 teraflops in 2012.

AWE suffered a fire in the explosives manufacturing area of the Aldermaston site. This led to prosecution by the HSE in 2013.

AWE celebrates 60 years of service to the nation, playing a vital role in the defence of the realm.

Strategic Defence and Security Review (SDSR) sets out Trident life and UK stockpile requirements to maintaining a credible, continuous and effective minimum UK nuclear deterrent.

The Anglo-French Treaty is signed by UK and French Governments, setting out a programme of defence cooperation between the two nations. The Treaty provides for collaboration through shared hydrodynamics facilities: one at AWE Aldermaston, the other in Valduc, France.

The ABL alliance, led by AWE and including Babcock International and Lockheed Martin UK, named as preferred bidder to deliver strategic weapons systems activities at Coulport.

Building work begins on Pegasus, the replacement materials processing facility at Aldermaston and also on Phoenix, the replacement conventional manufacturing facility at Burghfield.

Leo, the replacement component manufacturing and research facility at Burghfield fully operational.

David Newton, chief engineer, awarded an MBE in Queen’s Birthday Honours.

Construction work begins on the Technology Development Centre (TDC) to support the collaborative hydrodynamics work set out in the Anglo-French Treaty.

AWE provides Nuclear Security support to the Olympics in London.

Sponsored by the Home Office and the MOD, a new state-of-the art nuclear forensics laboratory opens, supporting national nuclear security.

Contract awarded to the ABL Alliance to manage the strategic weapons services at the Royal Naval Armament Depot, Coulport.

The Orion laser facility becomes fully operational.

Professor Peter Roberts, chief scientist, receives OBE in the Queen’s Birthday Honours.