Howard Mathieson, one of my colleagues in the Guild of One-Name Studies, has been working on producing maps showing the distribution of a surname in Ireland at parish level based on the Griffith's Valuation Indexes. He has very kindly produced some maps for me showing the distribution of the Cruise surname and related variant spellings. From 1848 to 1864 Ireland's Valuation Office conducted its first survey of property ownership in Ireland in order to determine the amount of tax each person should pay towards the support of the poor within their Poor Law Union. This survey became known as Griffith's Valuation after Richard Griffith who was the director of the office at that time. The survey recorded the names of both landlords and tenants throughout the country in both rural and urban areas, and it provides a snapshot of the population at a key point in Irish history, beginning at the time when the Great Famine was at its peak. It is a particularly important resource because no Irish censuses have survived prior to 1901 and it effectively serves as a census substitute. Griffith's Valuation can be found online on the Ask about Ireland website.
Howard's first map below shows the distribution of Cruise tenants in Ireland. It's interesting to see that there are still Cruises in the east of the country in Meath and Dublin, the counties where the Cruise family first held lands when they arrived in Ireland in the twelfth century, though there has been a noticeable westward drift into Galway and Mayo.
For anyone with an interest in surname mapping I recommend a visit to Howard's Geogenealogy website which provides a wealth of information on the subject and lots of interesting links.
© 2011 Debbie Kennett and Howard Mathieson