It's only been a few hundred years since the first lawyers were required to begin working in English, rather than French or Latin. There wasn't much progress after that, though, in making contracts, notices, and insurance forms, readable.
It's only in the past twenty years or so that pioneers like Cheryl Stephens have begun to bring readability to the documents that affect people's lives.
In 1987, Cheryl was working in a law firm, devoting more and more of her time updating the standard-form documents then in use. She thought there had to be another way, and began researching. By 1990, she was Associate Director, Research and Liaison for the Plain Language Project at the Continuing Legal Education Society of British Columbia.
In 1993 she and Kate Harrison founded an organization of plain language advocates, which today is the Plain Language Association International, now the primary organization promoting plain language internationally.