Oak Apple Day. Another name for Royal Oak Day (29th May), when people formerly wore oak leaves or oak apples in their hats to commemorate the manner in which the partisans of Charles II. welcomed his return to England on his birthday, 1651. This was, of course, in allusion to his concealment in an oak-tree near Boscobel House, Shropshire, after the battle of Worcester, on 3rd September previous...