Timeline of Sign Language Development & Recognition

Timeline of Sign Languages

From ancient philosophical observations to modern legal recognition - explore the journey of sign languages through history

4th Century BCE

Ancient Greece

  • • Plato in Cratylus notes that if humans lacked voice, they would communicate "by moving their hands, head, and other parts of the body."
  • • Aristotle claims that "those born deaf become senseless and incapable of reason," shaping centuries of negative attitudes toward deaf people.

16th Century

Spain - Early Education

  • • Pedro Ponce de León educates deaf children of nobility using manual signs.
  • • 1620: Juan Pablo Bonet publishes the first book on deaf education, describing a manual alphabet.

18th Century

France - Foundation of Modern Sign Language

  • • 1760: Abbé de l'Épée establishes the first free public school for the deaf in Paris. His work with natural signs leads to the foundation of French Sign Language (LSF).

19th Century

Expansion & Development

  • • 1817 (USA): American School for the Deaf founded by Gallaudet and Clerc. Birth of ASL.
  • • Distinct national sign languages develop independently in Europe and elsewhere (e.g., British Sign Language).
  • • 1864 (USA): Gallaudet University established as the first higher education institution for deaf students.

1880

Milan Congress (Italy) - Dark Period Begins

  • • Educators vote for oralism (speech/lipreading only), leading to bans on sign languages in schools.
  • • Sign languages are suppressed for decades, though preserved in deaf communities.

1960s

Linguistic Recognition

  • • William Stokoe proves ASL is a natural language with full grammar.
  • • Research expands globally, confirming the same for other sign languages.

1980s–2000s

Legal Recognition Wave

Deaf activism brings official recognition in many countries:
  • • Sweden (1981) – first country to officially recognize a sign language.
  • • South Africa (1996) – sign language recognized in the Constitution.
  • • New Zealand (2006) – NZSL becomes an official language.
  • • Croatia (2015) – adoption of the Law on Croatian Sign Language, granting it legal recognition.

2006

United Nations Recognition

  • • The Convention on the Rights of Persons with Disabilities (CRPD) recognizes sign languages as equal to spoken languages and obliges states to promote them.

2017

International Day of Sign Languages

  • • The UN General Assembly declares September 23 as the International Day of Sign Languages.

Click on any timeline item to expand and learn more about that period

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