If you creamed the sugar then that wouldnt have made much difference they still would rise.
Yorkshires require high dont they so confused how you cooked them both at the same time - 220???? First of all I would go out and check your oven temp, you can buy a thermometer for a few pounds. Make sure you are reading the dial correctly and preheating. Make sure fan assisted is turned off or down. 180/gas 4 is usual.
Check your flour too - did you use the correct ingredients? Did you over mix?
Dont be shy to check your cakes you can open the door only after 3/4 of the cooking is done. Not all ovens are the same so you may have to cook for longer than stated.
If the cakes didnt rise then there is a fundimental fault with either the recipe or your technique.
Yep thats a mystery to me how you cooked the both when they both need different temperatures, probaly like bacon said, maybe you didnt cream the butter and sugar enough, i beat mine for ages until practically white.
Hummingbird Bakery cookbook is dreadful - too many of the recipes didn't work and resulted in cakes that were either too sweet or didn't have enough flour so failed to rise or cook at all. Read the reviews on amazon. I wish I had before buying the book.