Greater Periwinkle (Vinca major) has the deserved reputation of being a tough as old boots groundcover that does well in shady spots. It flowers early in the year and is smothered in starry mauve blooms. Just about every stem droops down onto the ground and roots to create more growth. 

 My father tells me that Vinca major used to be advertised every Sunday in The Observer newspaper for purchase by mail order with the slogan "rolling and rollicking"!