BBC News Online looks at the significance of this time-honoured institution.

What is a loya jirga?

It is a forum unique to Afghanistan in which, traditionally, tribal elders - Pashtuns, Tajiks, Hazaras and Uzbeks - have come together to settle affairs of the nation or rally behind a cause.

The phrase loya jirga is Pashto and means "grand council". The institution, which is centuries old, is a similar idea to the Islamic "shura", or consultative assembly.

Historically it has been used to settle inter-tribal disputes, discuss social reforms and approve a new constitution. Hundreds of men wearing turbans, Persian lamb hats or embroidered quilt coats would pack into a vast hall. Long debates would take place in Pashto and Dari, with the inclusion of the occasional Koranic quote in Arabic.

Who are the delegates and how were they chosen?

About 1,500 delegates from all over Afghanistan took part in the loya jirga in Kabul.

More than 1,000 were elected in a two-stage process. Each district elected 20 people, who then held a secret vote to select one person to represent the whole district.

Each of the country's 362 districts had at least one seat, with further seats allotted for every 22,000 people.

No group was excluded from the assembly, but anyone alleged to have committed acts of terrorism or suspected of involvement in drugs, human rights abuses, war crimes, plunder or theft of public property is barred from attending.

Of the remainder of the seats, a total of 160 were given to women.

Nomads, refugees, academics, cultural institutions, social organisations and religious scholars were also represented.

The Taleban movement were not represented, but groups who share their political, social and cultural views sent representatives.

A loya jirga is seen as an essential process - one that is wholly Afghan. It is also seen as an inclusive institution. Women will attend for the first time.

It is an institution favoured by the Pashtuns in the south of the country, who believe they lost out during the Bonn political talks at the end of last year.

What about previous loya jirgas?

Perhaps the most famous loya jirga took place in 1747, when Pashtun tribal chiefs met in the southern city of Kandahar to elect a king. Deadlocked by nine days of debate, the loya jirga chose the king as the only man who had not spoken a word the whole time.

That was Ahmad Shah Durrani, the man who founded the state of Afghanistan.

In 1928, King Amanullah asked Queen Soraya to remove her veil at the loya jirga to win support for modernising reforms. However, this proved too much for the delegates, who fomented an uprising instead.