This book provides a lucid exposition how the fold and the operation of folding did appear in mathematics, and how it was constantly marginalized. It offers a study on the ways mathematical knowledge is marginalized, disappears, ignored or becomes obsolete. Spanning from 16th century to the 20th century, the volume gives for the first time an extensive historical study on the history of folding in mathematics. Thereby the book makes a valuable contribution to the field of history and philosophy of science, particularly the history and philosophy of mathematics.