Summary

  • On 17 August 1991, the Faculty of Physics, University of Warsaw established a TCP/IP connection to the European Internet using one channel of a leased BITNET line, a 9,600 bps modem and KA9Q software on an MS-DOS PC.
  • The date marks a working Internet path, not Poland’s first electronic mail, a new national backbone or general public access. A university retrospective records an earlier Kraków–CERN email in 1990 and dates wider global access to November 1991.

Analysis

A channel borrowed from another network

The most revealing detail in Poland’s 1991 Internet story is the connection’s small physical footprint. The Faculty of Physics, University of Warsaw says the historic exchange used one of four communication channels on a telecommunications line leased for the Polish BITNET network. A 9,600 bps modem carried the data. KA9Q, a TCP/IP implementation, ran on a personal computer using MS-DOS and performed the routing work. This was an Internet path assembled over capacity already paid for by an academic network, not a purpose-built national backbone.

That arrangement matters because it separates protocol from plant. TCP/IP supplied a way for independently administered networks to exchange packets. It did not supply a circuit, a modem, a router or permission to use another institution’s leased capacity. The physics group had to configure the equipment and make the route work. Marcin Gromisz later recalled that, even though the faculty had used TCP/IP internally, the team spent about a week preparing the hardware and software for the first exchange. The connection was a technical achievement built from a modest channel and local engineering.

What happened on 17 August

The date now used as the symbolic beginning of the Polish Internet is 17 August 1991. The Faculty of Physics’ retrospective describes an email milestone from its Warsaw site and calls the link the first Polish Internet connection fully based on TCP/IP. It identifies the route with Copenhagen and the European network, while also associating the message with DESY in Hamburg. Its account names Jan Sorensen, then head of the University of Copenhagen computer center, as the recipient of the first Polish mail sent via the Internet.

A 2026 retrospective from Poland’s Institute of Communications similarly describes a Warsaw–Copenhagen connection and an exchange linked to DESY.

Those descriptions do not preserve a complete original message header or packet trace, and they do not line up perfectly on the message’s endpoint. The defensible claim is therefore about the working connection and its role, rather than a reconstructed itinerary for a single email: Warsaw’s physics faculty established a TCP/IP path into the European Internet in August 1991. The exact mail endpoint remains uncertain in the public accounts reviewed here.

The word “first” also needs a boundary. The Warsaw faculty says the event was not the first email sent in Poland. It recounts that physicists at the Institute of Nuclear Physics of the Polish Academy of Sciences in Kraków received an email from CERN in November 1990, with TCP/IP used on part of the route. Electronic mail also moved through networks such as EARN/BITNET, X.25 and DECnet. These facts do not make the August 1991 route unimportant. They show why “first email,” “first packet using TCP/IP somewhere on a path,” and “a connection working fully under TCP/IP” are different historical claims.

Europe before global reach

The August link also did not make every destination immediately reachable. The Faculty’s account says the researchers had access to the European Internet in August and to the global Internet in November 1991. That sequence is a reminder that a successful international connection could still have a bounded network horizon. Reach depended on the route and the networks willing and able to exchange traffic, not simply on the presence of TCP/IP in Warsaw.

Nor should the date be confused with the creation of Poland’s country-code domain. IANA records 30 July 1990 as the .pl delegation date. NASK’s registry history lists the first operating .pl domains in 1991 and says the NASK Coordination Team at the University of Warsaw took on registry service in January 1992. A domain name made institutions easier to identify in the naming system; it did not establish that a working circuit existed. The address layer and the carriage layer developed on related but separate schedules.

The institutional setting was scientific. The Faculty retrospective places the work among physicists who needed to exchange research information with colleagues abroad, including at CERN. It says COCOM restrictions had impeded Polish researchers’ contact with academic networks in the late 1980s and were lifted in February 1990 after political change and pressure from physicists. That is the institution’s retrospective explanation; it does not mean every technical or administrative barrier disappeared at once.

NASK’s coordination network was formed in April 1991, before the celebrated August connection, while the first Polish Usenet group and web server followed in 1992 and 1993.

The evidence therefore supports a narrow but substantial conclusion. An academic team found a way to extend an existing leased line into a TCP/IP route to Europe, using equipment and software it could configure itself. The success widened the practical reach of Polish research networking. The sources do not establish a national user count, uniform university access, uptime, or household service. Public dial-up arrived later; it should not be projected backward onto a physics lab’s modem.

Sources