The sector of the Antarctic regions between the meridians of 30° and 90° W. is still largely unknown, and offers a particularly attractive field for exploration. It was the scene of the earliest discovery of land south of the Antarctic Circle, of the earliest and also of. the latest economic exploitation of the South Polar regions and it is the only part of the Antarctic where very large areas have been seen from the air but never visited on the surface either by sea or land. It is appropriate that a concise summary of the exploration of this region should be put together, in view of the expedition now being organised by John R. Rymill with the active support of the Royal Geographical Society, the British Government, the Discovery Committee and the Polar Institute.