A page from the naturalisation papers of Prince Ernest Leopold Victor Charles Augustus Henry Leiningen, from Germany. Certificate 1954 (catalogue reference: HO 1/60/1954)

What are these records?

These are naturalisation petitions completed by individuals applying to become British citizens between 1801 and 1871.

The records include:

  • all naturalisation applications to the Secretary of State, 1844-1871
  • some naturalisations by private Act of Parliament, 1801-1868
  • some letters applying for denization, 1801-1840 

Denization entitled people to certain rights, but not the full rights of a British citizen.

These naturalisation and denization papers make up The National Archives' series HO 1.

What information do they contain?

Until 1844 naturalisation was an expensive procedure which few people could afford. Therefore you can often find applications from royalty.

These case papers can provide quite detailed information on the applicant. 

They may contain the following information:

  • nationality
  • profession
  • family details
  • birth date
  • birth place
  • year of arrival into the UK
  • address of the applicant
  • character reference(s)

How do I search the records?

You can search the records by name in Discovery, our catalogue, using the search box below.

Search by name or country/state of origin.


What do the records look like?

A page from the record for Paul Julius Reuter (catalogue reference: HO 1/79/2403)

Some of these records include seals.

Click on the image to the right to get an idea of what the records look like. This is one page from the record for Paul Julius Reuter, founder of Reuters news agency (catalogue reference: HO 1/79/2403).

Why can't I find what I'm looking for?

If you are looking for enrolled copies of naturalisation certificates for this period, search within C 54. Copies of private Acts of Parliament are at the Parliamentary Archives.

If you are looking for case papers from 1871 onwards look in HO 45, HO 144, HO 382, and HO 405.

Related Guidance

Naturalisation and British citizenship