Kilflynn had been known as Stackstown, and the name remains geographically in Stack's Mountains south-east of Kilflynn. The family landowners, namely James (owner of Garrynagore, Gortclohy and Cloghanaleskirt), John (owner of Aghacoora), Richard (owner of Killaspicktarvin (and more northerly townlands)) and Thomas Stack (owner of Gortaneare, Ballyconnell, Castletown, Crotta, Glanballyma, Knocknahila, Cloonnafinneela, and Cappagh) forfeited their landed possessions because of their support for the Irish Rebellion of 1641 and the subsequent Catholic Confederation. The reconquest of Ireland between 1649 and 1652 by Cromwellian forces after the English Civil War resulted in the Act for the Settlement of Ireland of 1652 which required a survey for the redistribution of land (hence Sir William Petty's survey) often to invading soldiers in lieu of wages. Henry Ponsonby, the younger brother of Sir John Ponsonby (a colonel of horse in the New Model Army), was the recipient of most of the Stacks' (and others') confiscated land - much of which was profitable. This was reconfirmed in 1666, after the Acts of Settlement. Part of the Down's Survey was Pender's Census, taken between 1654 and 1659. The census refers to 'The Barony of Clanmorice', the townland of 'Crottoe' and the 'Tituladoe' as Henry Ponsonby Esq. The population for the whole of Clanmaurice is given as 1126, of whom 86 are English and 1040 Irish. There are 17 with the surname 'Stack' and 17 with 'FitzMorrice and MacMorrice'.