The Althingi is the oldest extant parliamentary institution in the world.Its establishment, as an outdoor assembly held on the plains of Þingvellir from about the year 930 AD,laid the foundation for an independent national existence in Iceland.
To begin with, the Althing was a general assembly of the Icelandic Commonwealth, where the country’s most powerful Leaders (goðar) met to decide on legislation and dispense justice.
Then, all free men could attend the assemblies,
which were usually the main social event of the year and drew large crowds of farmers and their families, parties involved in legal disputes, traders, craftsmen, storytellers and travellers. Those attending the assembly dwelt in temporary camps (búðir)
during the session. The centre of the gathering was the Lögberg, or Law Rock, a rocky outcrop on which the Lawspeaker (lögsögumaður) took his seat as the presiding official of the assembly. His responsibilities included reciting
aloud the laws in effect at the time. It was his duty to proclaim the procedural law of Althing to those attending the assembly each year. Read more here