The Greater Manchester Police Museum is proud to have one of the largest collections of surviving Alien Registers in the country. These rare books offer a rare window into the past and have helped people track down when and how their families and relatives arrived in the UK to start new lives.
This month marks 112 years since the passing of the Aliens Registration Act, and the beginning of modern Alien Registers. So, let’s look back at the origins of the Alien Registers, what they recorded, and how you can access these records at the GMP Museum.
The Aliens Registration Act
Whilst foreign visitors to the this country were required to register with local magistrates as far back as the early 18th century this was loosely enforced, leading to often ambiguously detailed ‘Alien Entries’ books. What is left of these records are now mostly owned by the National Archives, and have been used as the foundation of online family archives such as Ancestry.com.
What we would describe as modern ‘Aliens Registers’, came into being in the early 20th century. In August 1914, the Aliens Registration Act was introduced by the Parliament of the United Kingdom the day after its declaration of war on Germany marking the start of the First World War.
This was not a coincidence, and the purpose of the act was to allow authorities to monitor and control the movements of potential ‘enemy agents’.
The act was introduced and passed in its entirety in a single day and greatly expanded Parliament’s ability to place restrictions on foreign nationals (formally called ‘aliens’) in terms of how and if they could enter and leave the UK.
This included forcing ‘aliens’ to live in specific areas of cities, having their movements consistently reported to officials, and gave the police special powers of arrest for anyone suspected of violating the Registration Act.
The ability to enforce the Aliens Registration Act necessitated the creation of alien registers, enforced and managed by each local police force, which would track the arrival and departure of any ‘alien’ over the age of 16 in the country, alongside key personal information such as residency, prior occupation, and marital status and children.
The Alien Registration Act were maintained throughout the 20th century but was slowly repealed over the course of decades until only four sections of the original 1914 act remain, which are still enforced today.
What do Alien Registers look like, and what can you find in them?
Entries in Alien Registers usually offer a single line of information for each ‘alien’, and provides basic information about their:
- Registration Number (for their Alien Registration Card)
- Date of Entry to the UK
- Surname and Christian Names
- Nationality and Birthplace
- Assigned place of residence
- Current Occupation and Name of Employer
- Marital Status and Children
- History of Previous Places of Residencies
- History of Nationality, Citizenship and Foreign National Services
There are sometimes additional interesting details, such as making notes of major travel plans:
Some ‘aliens’ are tracked beyond the UK if they are expected to return to the country at a later date.
A common inclusion in the registers are red stamp entries which note when and where a migrant has arrived in the UK via air travel:
Whilst all foreign-born migrants arriving in the UK were generally monitored via the Aliens Registration Act, some ‘aliens’ were be more specifically targeted as suspected ‘enemy agents’ and be placed under even tighter restrictions or more thorough investigations.
For some, this went as far as to be interned in camps during wartime:
More than 30,000 people were detained by the UK government during WWII in places like “P” Internment Camp on the Isle of Man
Sometime, the Alien Registers also capture information about investigations carried out on foreign born residents, which reached its peak in the Cold War Era:
This person was interviewed as part of Operation Post Report (OPR), a decade spanning program to assess over 400,000 foreign nationals living in the UK and determined their potential risk to national security. Foreign nationals were required to attend one or more interviews with members of Special Branch, MI5.
The Greater Manchester Police Museum’s Collection of Alien Registers
The GMP Museum has over a dozen Alien Register books in its collection, the majority of which have been photographed, digitised and made ready for public viewing and research. Most of the Alien Registers in our collection come from the old Salford City Police force, with a few additional registers from Oldham and Rochdale Police forces. This collection is only partial, and there are many registration books lost to history, leaving gaps in the history of the registers.
Since the beginning of 2026, the Greater Manchester Police Museum has restarted its archival program, including access to this rare collection of Alien Registers.
How can you access the Museum’s Alien Registers
The majority of the alien registers at the GMP museum have been digitised and indexed for easier access.
To begin your journey with the registers, first use the index search engine to look for names of people you suspect will be in our Alien Registers. The index can be found here: Alien Register Index Search | Greater Manchester Police.
If you find a name in our index, this means we have their registration entry. Access to this entry depends on the date of the entry, and you may be required to provide proof that you are related to the those mentioned in the entries, or possibly proof of their death.
If you would like to gain access to any entry, please email us at police.museum@gmp.police.uk, and we will respond to you as soon as possible. We provide a free transcription service for these alien registration records, as well as an option for a £15 high-resolution digital copy of the original registration page which you can print out and keep forever.