The extended battlefield noted that different commanders had different views of the battlefield in geographical terms. The brigade commander had to consider actions beyond the immediate front lines, up to 15 km into the enemy's rear where his artillery was operating. The division commander considered the battlefield as far as 70 km out, while the corps commander had a field of view out to 150 km. Starry introduced the idea that there was not only a geographical dimension to the battlefield organization, but a time dimension as well; the brigade had perhaps 12 hours to respond to actions, while the division had 24 and the corps 72. It was this coordination both in space and time that defined the extended battlefield.