This book presents a corpus-based approach to the study of the spelling variation in words like colour, theatre and licence from a diachronic and a diatopic perspective. The analysis hinges on four processes of linguistic change that these words have undergone over time and are experiencing across varieties today: namely, standardisation and differentiation and simplification and Americanisation, respectively. The book thus highlights that spelling is neither arbitrary nor dependent on speech. Instead, it is shaped after social, cultural and political factors, thus making it as much as sociolinguistic product as any other linguistic level.