Complex sentence: The first HMS "Leeds Castle" was a Castle Class Corvette (though later on re-designated a frigate) built in 1944 the year of the famous D-Day landings and other famous events during WWII.
Split into simpler sentences: The first HMS "Leeds Castle" was a Castle Class Corvette (though later on re-designated a frigate). She was built in 1944, the year of the famous D-Day landings and other famous events during WWII.