Following the lockout (Serrata) of 1297, its membership was established on hereditary right, exclusive to the patrician families enrolled in the Golden Book of the Venetian nobility.
[2] The Great Council superseded the general assembly of the people (the Concio or Arengo, which was convened only to ratify laws and elect a new Doge.
[8] The "somewhat haphazard" election process placed enormous power on the hands of the very few electors, who were constrained only by force of custom to not abuse their position.
[8][10] Likewise complicated was the issue of foreigners, nobles from Venice's nascent colonial empire in the East or from Dalmatia,[8] or Venetian expatriate families returning to the metropolis after decades of absence, due to the fall of the Crusader states in the Levant in the late 13th century.
[11][15] This widening of the ruling class appears to have broadly satisfied ambitious men and calmed matters, although at least one commoner who thought that he should have been admitted to the Council, a certain Marin Bocconio, was hanged in 1300 for plotting to kill Gradenigo.
[14] It is notable that the reform passed during a nearly disastrous conflict with Venice's main rival, the Republic of Genoa, and that the common people made no serious move to oppose it.
[14][17] Regardless of their previous patrician or common origins, the now permanent and hereditary members of the Great Council henceforth constituted the nobility of Venice.
[20] Traditional historiography has lamented the Serrata as "the death of the Venetian republican system and the birth of a closed oligarchy",[17] but in actual fact, the effects of these reforms were broadly beneficial, and spared Venice the bitter factional rivalries that consumed the other Italian cities.
[17][19] For the remainder of the Republic's history, the Great Council was the supreme body of the state, replacing the virtually defunct Concio, which was formally abolished in 1423.
This need was identified already by Pietro Gradenigo, and a hall was enlarged for this purpose in the buildings lining the Molo, the embankment alongside the Doge's Palace.
[22] As the Council continued to increase in size in the early 14th century, and other magistracies were added to the government, it was decided that a new wing of the Doge's Palace be built alongside the Molo in order to house them.
[22] The hall was destroyed in the fire of 20 December 1577, in which the Doge's Palace suffered so much damage that for a time it was considered to tear it down and rebuild it to a new design.
In the end, it was decided to restore the building, and during this time, until 30 September 1578, the Great Council met in a storage shed in the Arsenal of Venice.
It was the Great Council, on 12 May 1797,[16] that declared the end of the Republic of Venice, by deciding - upon the Napoleonic invasion - to accept the abdication of the last Doge Ludovico Manin and dissolve the aristocratic assembly: despite lacking the required quorum of 600 members, the board voted overwhelmingly (512 votes in favor, 30 against, 5 abstentions) the end of the Venetian Republic and the transfer of powers to an indefinite provisional government.
The first volume of Annali Veneti e del Mondo written by Stefano Magno describes the origins of the Venetian noble families and presents the alphabetically arranged list with dates of their admission to Great Council.