This is the first book-length study of the relationship between Benedetto Croce (1866-1952), Giovanni Gentile (1875-1944), Guido de Ruggiero (1888-1948) and Robin George Collingwood (1889-1943). Though the relationship between these highly influential philosophers has often been discussed, it has never been studied comprehensively. On the basis of published and unpublished writings this study carefully reconstructs their debate on the relationship between thought and action, following their explorations of art, history, philosophy and action in the context of the First World War and the rise of Fascism and Nazism. This book unveils the hidden past of contemporary philosophy of history and divulges the last secret of Collingwood's Italian connection.