Complex sentence: The Grangethorpe site had from 1882 to 1936 been occupied by a large private house and gardens which were in use from 1917 to 1929 as the 2nd Western General Hospital, a military hospital.
Split into simpler sentences: The Grangethorpe site was occupied by a large private house and gardens from 1882 to 1936. From 1917 to 1929 it was used as the 2nd Western General Hospital, a military hospital.