Strong v Bird [1874] LR 18 Eq 315 is an English property law case.
The conduct of his stepmother (stopped paying the reduced rent as per their agreement) does not discharge the debt at law because there was no consideration provided for the release.
There are four conditions for the rule in Strong v Bird: In Re James,[1] Farwell J said, "The defendant by her appointment as one of the administratrices has got the legal estate vested in her and she needs no assistance from equity to complete her title.
Under these circumstances she cannot be compelled at the suit of persons claiming through the donor to surrender her property.
It follows that in my judgment the plaintiff here must recognize the title of the defendant to the property and no steps should be taken to recover it from her."