Who are they, and where is the movement headed?

- An unprecedented movement -

Everything started on October 1. Crowds gathered in the capital's usual protest spot of Tahrir Square after calls on social media to rally against corruption, lack of services and unemployment.

The first protester was shot dead that evening and as the death toll soared past 150 in the first week, the number of outraged Iraqis in the streets spiralled.

The rallies spontaneously mushroomed into the biggest grassroots uprising Iraq has seen in decades, with crowds hitting the streets of Baghdad and the Shiite-majority south almost daily, except for a three-week pause in October to allow for an annual Shiite religious pilgrimage.

But they were also the bloodiest, with nearly 550 killed in protest-related violence.

- For all, but led by none -

Although most protesters are young, the cause has united a vast range of Iraqis: university students skipping class, clerics in robes thumbing prayer beads, old-school communists and families waving Iraqi flags at their first-ever protests.

The rallies are relatively decentralised with each city organising its own marches and chants, but tent camps have sprung up across public squares to pressure authorities.

Some protesters spent weeks on end sleeping in the tents and marching during the day, as others came in to drop off free food or mattresses to keep the sit-ins going.

The protests have seen women participate in and even lead rallies, which is extremely rare in conservative areas.

No single leader has emerged, a fact authorities have used to discredit the movement but which activists say is a way to protect it, as prominence may expose them to threats.

The demonstrations have not reached the Sunni-majority west, where most fear a protest would be cast as a revival of Saddam Hussein's Sunni-dominated regime or the Islamic State group's ultra-conservative reign.

Nor have they gripped the Kurdish north, where a separate ruling system governs daily affairs.

- Demands partly met -

As the response to demonstrations grew increasingly violent, demands escalated from an end to corruption and unemployment to electoral reform, an independent prime minister and a total government overhaul.

In December, they scored two partial victories: then-premier Adel Abdel Mahdi resigned and parliament passed a new voting law.

But the bill fails to meet many of the protesters' demands, including smaller voting districts, and it has yet to be signed into law by the president.

And after two months of political stalemate, parties finally named a replacement to Abdel Mahdi -- Mohammad Allawi, a two-time communications minister.

Protesters rejected Allawi, saying he was selected by the very parties they had spent four months demonstrating against.

- A cleric's followers -

But one controversial Shiite cleric, Moqtada Sadr, immediately endorsed Allawi's nomination.

Sadr, who has a cult-like following across Iraq, backed the protests early on and his supporters were known as the best organised among the protesters.

But as protesters opposed the new premier, Sadr's diehard followers -- identifiable by the blue caps they wear -- have waged deadly attacks against anti-Allawi camps.

On Tuesday though, Sadr announced he was dissolving the "blue caps", the organised unit of his supporters accused of those deadly attacks.

The other clerical voice is Grand Ayatollah Ali Sistani, the top religious authority for most of Iraq's Shiites, who bolstered the movement when he called for political factions to drop support for Abdel Mahdi.

But many demonstrators complain he has not gone far enough in calling out the perpetrators of violence.

- No end in sight? -

Over the last four months, activists have faced a growing campaign of arrests, kidnappings and assassinations which they say is aimed at snuffing out their movement.

After Sadr peeled away, the movement lost much of the logistical support that had kept it going for months.

Protesters also fear their cause could be overshadowed by the threat of a proxy war between Baghdad's two main allies, Tehran and Washington, which could play out on Iraqi soil.

Already this year, the US killed Iranian general Qasem Soleimani and top Iraqi commander Abu Mahdi al-Muhandis in a drone strike on Baghdad, and Tehran responded with ballistic missiles on an Iraqi base hosting US troops.

Struggling for relevance, discouraged by the authorities' intransigence and now facing a new enemy in Sadr, the protest movement has seen its numbers dwindle.

"I'm staying in Tahrir. Iraq is more important than my studies," said Mustafa, a university student who has vowed to carry on.