The London Day Training College (LDTC), founded in 1902, soon became the leading institution for the study of education and for the training of teachers in England. In 1932 it was transmuted into the Institute of Education of the University of London. Its title and pre-eminence have continued to this day. In the period 1919-1945 it was closely, but by no means solely, identified with elements of the New Education. This article covers both the interwar period and the Second World War itself. It begins with a general introduction and then focuses upon the substantial contributions of four of the Institute's principal exponents of the New Education: John Adams, Percy Nunn, Susan Isaacs and Fred Clarke. Conclusions drawn demonstrate the complexities of the relationship between the New Education, the transformation of knowledge and the Institute of Education in this period. These were both individual and institutional and changed over time. For example, both Nunn and Clarke were advocates of freedom in education, and in society more broadly, but their concepts of freedom were construed in significantly different ways and contexts. (Contains 84 footnotes.)