## Facts

- A father verbally promised his son that a parcel of land would be his and handed over the title deeds to the son.
- Relying on this assurance, the son built a house on the land and incurred significant expenses, believing ownership would be formally transferred to him.
- Upon the father's death, the legal title to the land did not pass to the son, as the father's will did not confirm the earlier promise.
- The son brought an equitable claim, asserting that the father's assurance and his own reliance created an interest protected by proprietary estoppel.
- The court considered whether the son's reliance and incurred detriment, based on the father's actions, sufficed to create an equitable interest in the absence of a formal transfer.

## Issues

1. Whether a verbal assurance and delivery of deeds by the father, inducing reliance and detriment, could give rise to proprietary estoppel in the absence of formal transfer.
2. Whether the son's reliance and expenditure on building a house established an equitable interest that should be recognized by the court.
3. Whether equity could intervene to protect the son's interest despite strict legal formalities not being met.

## Decision

- The court held that the father’s actions, combined with the son's reliance and financial outlay, amounted to a clear assurance sufficient for proprietary estoppel.
- It was determined that the son’s building of the house and the related detriment justified equity’s intervention.
- The court recognized that denying the son’s equitable interest would be unjust, given the circumstances.
- It was found that proprietary estoppel was established, granting the son an equitable interest in the land.

## Legal Principles

- Proprietary estoppel arises where there is a clear assurance or representation, reliance on that assurance, and consequent detriment.
- Legal rights may be overridden where it would be inequitable to permit a party to deny what their representations and conduct have led another to expect.
- Equity may recognize and protect interests created through reliance and detriment, even when legal formalities are lacking.
- The detriment suffered need not be strictly financial and can include any significant loss or expenditure undertaken in reliance on the assurance.

## Conclusion

Dillwyn v Llewellyn established that proprietary estoppel can confer equitable rights where one party has relied on another’s assurance to their detriment, and equity may intervene to prevent injustice even if strict formalities for transfer are absent; this case remains a foundational authority for the doctrine in property law.

Dillwyn v Llewellyn (1862) 2 Giff 517