A Penchant for Plus Fours & Fair Isle
If reading is believing, Plus Fours didn't really exist prior to the First World War. They were a development from the traditional military or sporting 'knickers' garment which stopped at the knee and were popular for walking in. However, the cuffed knee made the garment uncomfortable for other activities (i.e. horse riding, climbing etc). To give the knee more freedom of movement, an extra 4 inches of fabric was added to below the knee to create a 'bagged' effect, and thus the name, Plus Fours', stuck.
Here's Edward VIII working the fair isle look with a stout pair of tweed Plus Fours. Edward has a lot to answer for in making the Plus Four so popular in the 1920's right up to their fall from favour in the 1940's. After Edward's diplomatic trip to America in 1924 he apparently started a craze for the bagged bloomer in the States too..