is offering visitors a chance to comb through historical records in search of Irish bloodlines as part of a free trial on St. Patrick's Day.

The website usually charges users a monthly fee to get access to historical records from around the world.

But on Thursday, until 11:59 p.m., any visitor to the site will be able to search millions of Irish records, including numerous recently digitized and indexed from the Catholic parish.

Irish genealogist Michael Brophy told CTV News Channel that this will give the chance Canadians who are part of the Irish diaspora a chance to get in touch with their roots.

"I think it is important because it provides the most direct link for folks of Irish-Catholic ancestry to trace their Canadian-Irish-Catholic heritage before the great Irish potato famine, which started in 1845 and lasted into the 1850s," said Brophy.

Boatloads of immigrants came to Canada to escape the period of mass starvation and disease that claimed roughly 1 million lives.

Irish-Canadians are currently the fourth largest ethnic group in Canada with 4,544,870 among their ranks, according to the National Household Survey in 2011.

Brophy said's records are particularly useful because they've incorporated and indexed 10 million records of Ireland's Catholic parish, some of which date back to 1655.

He added these records are the "best direct link" for heritage hunters because official documentation of births, marriages and deaths didn't start across the board until 1864.

Meanwhile, the parish records contain information about baptisms, marriages, confirmations and burials that date back much further.

The National Library of Ireland undertook the massive, multi-year effort to digitize the records over the past several years, and they were released last summer on its website. However, they require visitors to know their family's parish.