When the 1901 census of England and Wales first became available online in January 2002, it proved so popular that within hours the flood of customers had managed to make it useless.

These days, the Web site run by the British government’s Public Record Office is operating much more smoothly. And for Latvians seeking to uncover their family history, the 1901 census might even reveal a lead or two, although historical accounts of Latvians in the United Kingdom in the early 20th century suggest that few will be found.

A quick test of the online service uncovered at least some names, such as Gothard Ohsolin (Gotārds Ozoliņš), August Upmal (Augusts Upmals) and Alfred Putning (Alfrēds Putniņš).

Detailed data from the 1901 census only became available after a 100-year restriction on the release of information expired. The Public Records Office transferred the hand-written census logs into a database and created digital copies of the original pages. Entries for the 32 million residents of England and Wales are now easily searched.

But be prepared to pay if you want any details about your ancestors, or if you want to see a digital version of the page on which your ancestor’s name appears. The online service charges a minimum of GBP 5 for each 48-hour session. A temporary account is easily created by providing credit card details.

Before using the service it helps to have as much information about your ancestor as possible, as well as to remember that Latvian surnames in 1901 usually were spelled without the use of diacritical marks and that they may well have been spelled differently once immigrants arrived in their new homes.

For example, Ozols and Ozoliņš are common Latvian surnames. But searching for those names yielded no results. Using the “wild card” asterisk symbol and searching for Osol* and Ohsol* uncovered at least two individuals: Gothard Ohsolin, 45, an able-bodied seaman aboard the Janow, and Adam Osol (Ādams Ozols), 40, an able-bodied seaman aboard the S.S. Olivia.

A handy function of the database allows the user to see who else was living at the same address on the evening of March 31, 1901, when the census was recorded. In the case of ships in port, details are offered on who else was aboard a particular vessel.

And so, for example, also aboard the Janow with Ohsolin was at least one other Latvian, 26-year-old August Upmal.

It can only be assumed, based on their surnames, that these individuals were Latvians. The 1901 census information often is incomplete or vague. Ohsolin and Upmal are listed as having been born in Russia, but specifically where is not revealed. In this case, census information about the vessel, the Janow, helps reduce uncertainty. The Janow, according to the record, was a 198-ton vessel based in Pernau, Russia (modern-day Parnu, Estonia, north of Latvia).

Similarly, a search for Kalnin* turned up Rembert Kalning (Remberts Kalniņš), a 30-year-old master aboard the Catharina. He was joined on the ship by six other men, including 21-year-old mate Alfred Putning. And the Catharina, the census records show, was a 223-ton vessel based in Rīga.

Apparently missing from the census data are entries for some Latvians whose presence in Britain has been documented elsewhere. For example, socialists Ernests Minka and Ernests Rolavs, who helped publish the revolutionary newsletter Latviešu Strādnieks in London, can’t be found, although both should have been in England when the census was taken.

According to the 1995 book, Latvieši Lielbritanijā, by the turn of the 20th century, only a few Latvians were living in Great Britain. In the port at Cardiff, Wales, ships from Latvia were frequent visitors. In 1900, according to the book, the Rev. Konstantīns Ūders began serving a congregation of Latvians and other ethnic groups. But the online census records also don’t seem to hold information about the minister.

Many more Latvians emigrated to Great Britain after the failed 1905 revolution in Latvia.

The online 1901 census records only cover England and Wales. The census records for Scotland and Ireland are not available online.