This surname is Irish and was originally a descriptive nickname for a land owner. Recorded in the spellings of O' Shelley and Shelley in Munster and as Shally in Connacht, with the much rarer forms of Shaloe, Shalloe, Shallow, and Shalloo, being found originally in Counties Clare and Tipperary, although these counties are far apart. However spelt the name derives from the Ancient Gaelic O' Sealbhaigh, meaning "the descendant of the land owner" or similar, one who held possessions. In Ireland there is confusion because many of the name holders spelt Shelley do have English ancestry, English Shelley's holding lands in Ireland since at least the 16th century. This makes accurate genealogy very difficult, a difficulty compounded by the fact that in 1922 during the Civil War and after the "British" had left, the IRA in an act of lunacy and vandalism destroyed the Public Records Office in Dublin. This building contained irreplaceable records, some of the most ancient in the world, and going back to the very begining of written history. Examples of recordings taken from surviving registers include Michael Shalloe of Kilkeshen, County Clare, on Octber 18th 1864, James Shaloe of Shinrone, County Tipperary, on January 13th 1866, whilst the earliest we have is that of Margaret Shallow, who married Benjamin Carlow at St Munchin's church, Limerick, on November 16th 1764. Over the centuries the surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.