This article presents first the history of the optical fiber transport networks, from the introduction of the first high capacity systems in the 1990s to the 10 Gbit/s per channel WDM (Wavelength Division Multiplexing) systems deployed today, and the tremendous evolution of performance within this period. The effects of propagation in optical fibers and their consequences for optical system engineering, the architecture of today's optical transport networks, the choices made in France are recalled. We then have a look at the future of optical transport networks from an operator's point of view: the expected evolutions in terms of transmission system capacity and network architecture are presented. We conclude that capacity, transparency, and agility are the main drivers of the evolution of optical fiber transport systems and networks and that a lot of changes have yet to be expected in these domains during the next decade.