There are a few reasons your cake did not rise: - The butter and sugar weren't creamed for long enough. This steps creates lots of tiny air bubbles that will expand in the oven and make the cake rise. If not done properly, you will loose that extra leavening. - The Baking Powder or Baking Soda were out of date and not as active. - The oven temperature was too low. Baking cakes are a lower temperature make your cakes rise more slowly, resulting in flatter cakes.