Complex sentence: Considered to be at a peak in the time between the first and second World Wars it forms a late part of the Industrial Age and was utimately eclipsed by the Atomic Age beginning in 1945.
Split into simpler sentences: Considered to be at a peak in the time between the first and second World Wars it forms a late part of the Industrial Age. It was utimately eclipsed by the Atomic Age beginning in 1945.