The Roman Senate

It was one of the first collective government institutions. It functioned in the Ancient Rome and had about 300 hereditary peers. Its main function was to advise the governing magistrates on religious matters and foreign policy.
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Image: Cicerón denounces Catilina, by Cesare Maccari, 1889.
Scene from a speech delivered by Cicero, Consul of the Roman Republic, in the Roman Senate.

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Image: Wikimedia Commons.

The Althing of Iceland

The Iceland Parliament was founded in 930. It is considered the oldest parliament in the world. It served as a meeting of leaders who approved measures and it began to legislate in the thirteenth century. In the image you can see its precinct, formally it is called Althing or Althingi.

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Image: Trevor Mogg / Alamy Stock Photo.

Cortes de León

They were held in León, in what is now Spain, in the year 1188. They had three social strata: clergy, nobility, and representatives of cities. In the courts, the set of decrees called the "Magna Carta Leonesa" was created.
Below is a photograph of the Basilica of San Isidoro de León, the site where the Cortes were held during the reign of Alfonso IX of León.

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Image: Wikimedia Commons.

British Parliament

It dates back to the year 1154, with the emergence of the Great Council, which met only three or four times a year. It was until the year 1258 that it began to be designated as Parliament. By 1295, the "Model Parliament" met, considered the first official Parliament of England.
In the picture you can see the interior of the plenary hall of the House of Commons of the British Parliament during a session of questions for the Prime Minister.

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Bill of Rigths

The Bill of Rights was drawn up in 1689 in England. It is considered a relevant text because it is the precedent of the Declaration of Independence of the United States (1776) and the Declaration of the Rights of Man and of the Citizen (1789).

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Image: Bill of Rights Institute.