This chapter describes the domestication of cattle and the origins of many breeds found in the world today. The breeds are grouped into biological types, based on their size, muscularity and propensity to fatten, and the commercial role of each type is discussed. The relationships between biological types and carcass and meat quality are examined, and the breeds are identified as repositories for specific traits of value to the beef industry. Traditional methods of improving carcass quality through phenotypic trait selection and opportunities to improve meat quality through the application of genomics are discussed.