My comments in the following post are in bold:
1. Dictionary Of The Landed Gentry of Great Britain & Ireland, Sir Bernard Burke. London. 14th edition, 1863.
2. The History, Architecture And Antiquities Of The Cathedral Of Church of St. Canice, Kilkenny, by Rev. James Graves, A.B. and John G. Augustus Prim. Hodges, Smith & Co. Dublin, 1857.
3. City of London.gov (list of Mayors of London, 1189 - present)
4. Wikipedia, List of Mayors of London
5. British History Online, created and maintained by the Institute of Historical Research and History of Parliament Trust.
"One of the Lord Mayor's family is stated to have gone to Ireland, a major in Cromwell's Army, and to have been the ancestor of the Very Rev. Thomas Pack, dean of Ossory, and of the Packs of Kilkenny" (Burke).
The Lord Mayor Burke refers to is Christopher Pack. He served as Lord Mayor in 1654 (see List of Lord Mayors of London, Wikipedia).
"The Pack family was originally seated in Leicestershire. Simon, son of Christopher Pack, settled in London at the end of the sixteeth century, and became Lord Mayor of that city..." (The writers are incorrect. Christopher Pack was Lord Mayor in 1654. There are numerous sources, including the City of London's own history sites that show this information is incorrect. Simon was never a Lord Mayor. "The Irish branch of the family claims to be derived from a younger son of this gentleman, who, having been engaged in the Wars of the Commonwealth, came over and settled in the Queen's County, and his descendant, Thomas Pack, of Ballinakill, married a Miss Kiley, and had three sons, of whom the eldest was the Very Rev. Thomas Pack, Dean of Ossory; the second was the Rev. Richard Pack, Pincipal of Kilkenny College; and the third, Samuel Pack, Esquire, of Dublin, emigrated to America. This is the family tradition." (Graves and Prim). Graves and Prim further state that they can not verify that Sir Christopher was in fact the forefather to the Packs of Kilkenny (Ireland).