When considering the Australian branch of the family; the first question to ask is free settler or transported convict. This blog will concern the various online databases to document convicts.
Convict transportation is important in Irish research is because births places are usually documented. Thus, if you cannot find Irish origins using records where your ancestor immigrated; then look for the relative who was transported.
The main database is “Ireland-Australia Transportation Index (1791-1853)” on the National Archives of Ireland: www.nationalarchives.ie/topics/transportation/search01.html However, be aware many of the transportation records pre-1836 have not survived.
From the Australian side, are sources from which to document the convict after arrival. It has been estimated 40,000 Irish convicts were transported between 1791 and 1853.
The Tasmanian Archives has a “Names Index” comprising several databases: www.linc.tas.gov.au/tasmaniasheritage/search/name-indexes/nameindexes The “Index to Tasmanian Convicts” is a comprehensive index of all convicts transported to Tasmania and those convicted in the colony from 1804-1853 when transportation ceased.
The State Archives collection of New South Wales has a wealth of varied databases on their website under “Indexes Online”: www.records.nsw.gov.au/state-archives/indexes-online/indexes-online This includes “Convict Index” which contains about 120,000 entries combining eight indexes covering 1810-1879. Other databases include “Sentenced Beyond the Seas” which covers Australia’s early convict records (1788-1801) and includes 12,000 names. “Applications to Marry, 1821-51” provides details for parties asking permission to marry. “Convict Exiles, 1849-50” which covers when transportation ceased to NSW in 1842, exiles who had served part of their time in a British penitentiary were granted pardon or ticket of leave on arrival in the Colony from 1846-50. “Convict Pardons, 1791-1873” documents convicts who received life sentences although usually pardoned.
The Internet holds a wealth of information on convicts. Again, it may be among this segment of the population that a birth place in Ireland is preserved.