Complex sentence: Educated at Wolverhampton Grammar School and Wadham College, Oxford, he joined the Home Civil Service in 1925 and attained the grade of Principal in 1933 and of Assistant Secretary in 1938.
Split into simpler sentences: Educated at Wolverhampton Grammar School and Wadham College, Oxford, he entered Home Civil Service in 1925. He attained the grades of Principal in 1933 and Assistant Secretary in 1938.