Complex sentence: When all operations on the Anglo-Canadian front were ordered to halt at 21:00, only one unit had reached its D-Day objective, but the 3rd Canadian Infantry Division had succeeded in pushing farther inland than any other landing force on D-Day.
Split into simpler sentences: When all operations on the Anglo-Canadian front were ordered to halt at 21:00, only one unit had reached its D-Day objective. Despite this, the 3rd Canadian Infantry Division had succeeded in pushing farther inland than any other landing force on D-Day.