Several Hacketts and Hakets appear in the lists of sheriffs of Counties Tipperary and Waterford and as members of parliament for Fethard up through the sixteenth and seventeenth centuries.
Members of the Hackett family accompanied Richard "Strongbow" de Clare, 2nd Earl of Pembroke during his invasion of Ireland.
The Hacketts were subsequently granted estates in the modern counties of Kilkenny, Carlow and Kildare and thus became the principal holders of land and one of the most influential families in Ireland.
Further, the Fiants of Henry VIII and Edward VI indicate that in the sixteenth century there were also Hacketstowns, or Ballyhackett, in Counties Dublin and Kildare.
An early Coat of Arms was worn by William de Hackett of Cashel in County Tipperary who founded a Franciscan Friary there in the 13th Century.
Another Coat of Arms was granted to Sir Thomas Hackett, descended from an ancient family long settled in Ireland and Lord Mayor of Dublin in 1688.
The coat of arms bore "the splendid blazon of a field gules thereon three hakes argent haurient in fesse, on a chief or three trefoils slipped proper.
The crest being, out of a mural coronet argent, an eagle displayed with two heads sable, with the motto; Spec mea Deus".
Translated, this reads "On a red shield are three silver hake fish (a pun on the name Hackett) on the top fourth (Chief) are three shamrocks on a gold background.