Chancellor House is a place where the legal firm of Nelson Mandela and Oliver Tambo was located in the 1950s. It was the first firm of African lawyers in Johannesburg and one of the few that was willing to take cases on behalf of the majority of South African citizens were experiencing various forms of discrimination, oppression and repression.  Former President Nelson Mandela, in his book, A Long Walk to Freedom describes the import of his firm:

"'From the time when the offices began to operate, Mandela and Tambo were besieged with many clients. For Africans, we were the firm of first choice and last resort. To reach our offices each morning, we had to move through a crowd of people … I realised quickly what Mandela and Tambo meant to ordinary Africans. It was a place where they could come and find a sympathetic ear and a competent ally, a place where they would not be either turned away or cheated, a place where they might actually feel proud to be represented by men of their own skin colour. This was the reason I had become a lawyer in the first place, and my work often made me feel I had made the right decision".

In 1960, after the State of Emergency was declared and after Tambo went into exile, Mandela was forced to leave these premises and practiced law from Ahmed Kathrada’s nearby flat – 13 Kholvad House. But the office of Mandela and Tambo is of great significance as this is where South Africa’s most famous citizens shared a place of work together for the last time.

For various reasons, Chancellor House fell into a state of disrepair through the years. Following South Africa's democratic transformation in 1994 a number of historical and cultural activists took up the call for the restoration of this building and the preservation of its precious heritage.

It became an urgent concern when the then owners announced plans to demolish it to make way for a parking garage. Fortunately reason prevailed and it was declared a provisional national monument in 1999.

Trace was brought in by the JDA to research the history of the building and design an exhibition as a ‘shop window’ space on street level along the length of the building. This is a unique concept as it means that passers-by are able to learn more about the building without having to step inside. This innovative format has attracted the attention of many people in the area and has created a new way of transforming former historical sites of significance without building a conventional museum. The street exhibition has featured regularly in magazines and newspapers especially in recent times with the spotlight on former President Nelson Mandela.