Hardly a week – it seems – goes by without another estoppel case hitting the database. This is a far cry from the original conception of estoppel which focused on the actions of the landowner and operated as an evidential bar, and it represents an extended application of the modern approach to estoppel found in Taylors Fashions v Liverpool Victoria Trustees. I always thought that a “floodgates” arguments was overrated and a poor substitute for analysing the principled boundaries for the operation of legal norms. But, it is not exaggerating to recognise that Gillett v Holt opened two whole new chapters in the law of proprietary estoppel: first, it demonstrated that estoppel could be used to advance testamentary expectations and thereby subvert testamentary freedom; secondly, it brought a whole new dimension to arguments over ownership of the family farm.