The book surveys mathematical education in Iceland from medieval times to the present. Its main focus is on important influences from the international 'modern' mathematics reform movement in the 1960s, promoted by the OECD. At that time mathematics education in Iceland had drifted into stagnation, characterized by shortage of teachers, curricula and textbooks. In spite of turmoil and confusion in the Icelandic school system, caused by the introduction of 'modern' mathematics, it had significant positive impact. It stimulated the creativity and initiative of a generation of teachers and played an important role in the transformation of Icelandic society. Icelanders came to recognize the importance of mathematics for technical and economic progress and for its inherent cultural value.