This dissertation poses the question whether the doctrine of Proprietary estoppel can provide the basis for recognising a range of rights in relation to the family home. This question also necessitates a consideration of the doctrine of constructive trusts and the acquistiton of rights under the Limitation Acts. The dissertation proceeds to consider whether the nature of the relationship between parties to a dispute concerning the family home constitutes a heavily determining factor in the outcome of that dispute. It will emerge that in practice the doctrine of propietory estoppel operates differently in respect of each of three broad categories of licence relationships:- i) <i>Licence granted by resident family member</i>. In this first category both parties are members of the same household who jointly occupy the property as their family home. In this context the term 'family' is used in a very broad sense. It includes not only relationships of blood and afinity but also all those relationships where there is interdependence and a common concern by the participants for each other's welfare. The shared values of the participants in these relationships and the meaning they attach to each other's conduct may well be similar to those shared values and meanings which exist between members of the family in its stricter legal sense. The concept of 'family' is as much a functional notion as a decscriptive term. This broader concept of the family is more akin to the term 'household'. ii) <i>Licence granted by non-resident family member</i> In the second category the licensor and licensee are members of the same family but do not share the same house. iii)<i>Licence granted by a stranger</i> In the third category the licensee and his family have been granted occupation rights by someone who is not a member of their family. Since the decision of the House of Lords in <i>Gissing</i> v <i>Gissing</i> it has generally been accepted that the elements necessary to found an implied trust (whether resulting or constructive) of the family home are limited in scope. The longstanding equitable doctrine of propietory estoppel has therefore been revitalised, in an attempt to fill the gap left by the decision in <i>Gissing</i>. The theory of Proprietary estoppel aims to avert the unconscionable outcome which would otherwise result where one party has been encouraged by the holder of a legal title to alter his position to his detriment in the expectation of some entitlement in the property concerned. This dissertation contains an analysis of the case law of England, Northern Ireland, the Republic of Ireland, Australia and New Zealand, for the purpose of considering which forms of unconscionable conduct in the familial context are sufficient to give rise to the equity of Proprietary estoppel. These jurisdictions have been selected because in each, Proprietary estoppel has been used as a means of protecting rights in the family home. Each of the selected jurisdictions has recognised the limitations of the doctrine of constructive trusts in achieving that end. Canadian case law is also analysed to illuminate the relationship between the doctrine of Proprietary estoppel and the doctrine of constructive trusts. It is noticeable that the Canadian courts have effectively ceased to use the doctrine of Proprietary estoppel in the family home context, having replaced the doctrine by a creative use of the constructive trust.