* Sign language is not a single entity: There are hundreds of different sign languages around the world, each with its own unique history and development.
* Sign languages have existed for millennia: Deaf people have always communicated through sign language, dating back to ancient times. There is evidence of sign language use in ancient Egypt, Greece, and Rome.
* Sign languages are constantly evolving: Just like spoken languages, sign languages change and develop over time. They are influenced by factors like cultural exchange, technological advancements, and the needs of the deaf community.
However, we can talk about some key milestones:
* 18th century: The establishment of schools for the deaf in Europe marked a period of increasing interest in sign language and its potential for education.
* 19th century: The development of sign language dictionaries and grammars, as well as the formalization of sign language instruction, helped to standardize sign languages and increase their visibility.
* 20th and 21st centuries: The deaf community's growing recognition of the value of sign language and its role in Deaf culture led to a period of sign language revitalization and advocacy.
In summary: Sign language has been around for a long time, and its development is an ongoing process that continues to this day. There is no single date for its development, but rather a rich history of innovation, adaptation, and cultural expression.