On this day March 20, 1883
Eleven countries signed the Paris Convention for the Protection of Industrial Property, one of the first intellectual property treaties.
The Convention was one of the first intellectual property treaties. As a result of this treaty, intellectual property systems, including patents, of any contracting state are accessible to the nationals of other states party to the Convention.
The “Convention priority right“, also called “Paris Convention priority right” or “Union priority right“, was also established by this treaty. It provides that an applicant from one contracting State shall be able to use its first filing date (in one of the contracting State) as the effective filing date in another contracting State, provided that the applicant files another application within 6 months (for industrial designs and trademarks) or 12 months (for patents and utility models) from the first filing.
After a diplomatic conference in Paris in 1880, the Convention was signed in 1883 by 11 countries: Belgium, Brazil, France, Guatemala, Italy, the Netherlands, Portugal, El Salvador, Serbia, Spain and Switzerland.
The Treaty was revised at Brussels, Belgium, on December 14, 1900, at Washington, United States, on June 2, 1911, at The Hague, The Netherlands, on November 6, 1925, at London, United Kingdom, on June 2, 1934, at Lisbon, Portugal, on October 31, 1958, and at Stockholm, Sweden, on July 14, 1967, and was amended on September 28, 1979.
The Convention now has 172 contracting member countries,  which makes it one of the most widely adopted treaties worldwide. Notably, Taiwan and Kuwait are not parties to the Convention. However, according to Article 27 of its Patent Act, Taiwan recognizes priority claims from contracting members. The Paris Convention entered into force in Thailand on August 2, 2008, bringing the total number of Nation States party to that Convention to 173. 
Contracting members include: Albania; Algeria; Andorra; Angola; Antigua and Barbuda; Argentina; Armenia; Australia; Austria; Azerbaijan; Bahamas; Bahrain; Bangladesh; Barbados; Belarus; Belgium; Belize; Benin; Bhutan; Bolivia; Bosnia and Herzegovina; Botswana; Brazil; Bulgaria; Burkina Faso; Burundi; Cambodia; Cameroon; Canada; Central African Republic; Chad; Chile; China; Colombia; Comoros; Congo; Costa Rica; Croatia; Cuba; Cyprus; Czech Republic; Côte d’Ivoire; Democratic People’s Republic of Korea; Democratic Republic of the Congo; Denmark; Djibouti; Dominica; Dominican Republic; Ecuador; Egypt; El Salvador; Equatorial Guinea; Estonia; Finland; France; Gabon; Gambia; Georgia; Germany; Ghana; Greece; Grenada; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Holy See; Honduras; Hungary; Iceland; India; Indonesia; Iran (Islamic Republic of); Iraq; Ireland; Israel; Italy; Jamaica; Japan; Jordan; Kazakhstan; Kenya; Kyrgyzstan; Laos; Latvia; Lebanon; Lesotho; Liberia; Libya; Liechtenstein; Lithuania; Luxembourg; Madagascar; Malawi; Malaysia; Mali; Malta; Mauritania; Mauritius; Mexico; Moldova; Monaco; Mongolia; Morocco; Mozambique; Namibia; Nepal; Netherlands; New Zealand; Nicaragua; Niger; Nigeria; Norway; Oman; Pakistan; Panama; Papua New Guinea; Paraguay; Peru; Philippines; Poland; Portugal; Qatar; Republic of Korea; Romania; Russian Federation; Rwanda; Saint Kitts and Nevis; Saint Lucia; Saint Vincent and the Grenadines; San Marino; Sao Tome and Principe; Saudi Arabia; Senegal; Serbia; Seychelles; Sierra Leone; Singapore; Slovakia; Slovenia; South Africa; Spain; Sri Lanka; Sudan; Suriname; Swaziland; Sweden; Switzerland; Syrian Arab Republic; Tajikistan; The former Yugoslav Republic of Macedonia; Togo; Tonga; Trinidad and Tobago; Tunisia; Turkey; Turkmenistan; Uganda; Ukraine; United Arab Emirates; United Kingdom; United Republic of Tanzania; United States of America; Uruguay; Uzbekistan; Venezuela; Vietnam; Yemen; Zambia; and Zimbabwe.
Former member state: Orange Free State 1899 – 31 May 1902
The Paris Convention is administered by the World Intellectual Property Organization (WIPO), based in Geneva, Switzerland.