Catherine Vadney hired an attorney to draft a deed conveying her house from her sole ownership to joint ownership with her son, Peter Vadney. The deed, as executed, did not specify what type of tenancy Catherine Vadney intended to create. After Catherine died, Peter Vadney served as the executor of her estate. Peter believed that his mother’s deed had created a joint tenancy with a right of survivorship automatically conferring title upon him at Catherine’s death. Under that belief, Peter excluded the house from the list of estate assets to be equally distributed among all Catherine’s children in accordance with her will. Catherine’s three other children argued that the absence of express language creating a joint tenancy rendered the deed a conveyance of tenancy in common by action of New York statutory law. They asserted that a one-half interest in the property should have been included among the assets of Catherine’s estate. Peter Vadney petitioned the court to reform the deed in conformity with his understanding of his mother’s wishes. The probate court held that extrinsic evidence was not admissible to reform the deed and denied Peter’s petition. Peter appealed and the appellate court reversed the probate ruling. The remaining children petitioned the court of appeals for review.