The paper is designed of deeply analyze the norms contained in the projects of property law of 1937 and 1939 as well as in the project of statute of 2000 on the amendments to the Polish Civil Code and the amendments to the following pieces of statutory law: on perpetual books and mortgage, on the code of civil procedure, on debentures and mortgage banks, on the law of notary’s offices and on presently functioning regulations detectable in the law on perpetual books and mortgage and referring to the instrument of disposing of the vacated mortgage place. The new institution which substantially transformed the previously known model of mortgage succession was introduced into the Polish system by the amendment to the law on perpetual books and mortgage and by amendments to some other statutory laws, the amendment coming into force on 20 February 2011 after the 18-month lasting vacatio legis. The authoress analyses the topic of her research by exploiting the historical method and that of comparative type. Among the most important observations that she makes is the one which points to the present-day regulation of the institution of disposing of the vacated mortgage place as anchored in the project of property law of 1939. While summing up her study, the authoress stresses that the Polish legislator tends toward emphasizing the positive aspects and eliminating the negative ones in the regulations detectable not only in foreign systems but also in the aforementioned projects of 1937, 1939 and 2000. The authoress points out that the legislator was not indifferent to polemics that were published in legal journals and referred to the respective projects. What testified to this was the introduction into the Polish legal system of the concept of disposition of the vacated mortgage place.