Complex sentence: It opened on 28 April 1941 as Spalding The Gleed Senior Council School and comprised boys' and girls departments which from 1946 were regarded as separate schools under the same management.
Split into simpler sentences: It opened on 28 April 1941 as Spalding The Gleed Senior Council School and comprised boys' and girls. Departments which from 1946 were regarded as separate schools under the same management.