Jaqueline Tyrwhitt (1905–83) was a town planner, editor and educator who was at the centre of a group of people who shaped the post-war Modern Movement. Tyrwhitt's great contribution, especially to the planning arm of the Modern Movement, the new field of urban design and the new science of ekistics, is under-recognized, largely because she worked willingly as the ‘woman behind the man' – notably as a disciple of Patrick Geddes, translator and editor of Sigfried Giedion, and collaborator of Constantinos Doxiadis. In doing so she extended their influence greatly and shaped the work of many people. Histories of planning lose much by omitting the contribution of collaborative, catalytic actors such as Tyrwhitt, whose career serves as a touchstone for this era, considered to be a watershed in the history of planning as an intellectual and professional movement. This paper sheds light on Tyrwhitt's contribution through a chronological narrative, interweaving the biographical facts of her career with the larger themes her work engages in the broadest sense: the globalization of planning and urban design as an intellectual and professional movement as part of the larger civilizational transformation – the emergence of countervailing, ‘postmodern' globalism, a humane, ecological world view very much like Geddes' Neo-Technic Era.