They swayed and chanted in passionate prayer. They blew on rams' horns. They massed in the centre of town and marched in candlelight procession at the Prime Minister's official residence.
And, having closed their schools for the day, unprecedentedly, they brought their children with them for much of the day.
Tens of thousands of Jewish settlers from the West Bank held a series of demonstrations in Jerusalem yesterday. Their cause: to persuade first a majority of politicians, and then a majority of ordinary Israelis, that the Prime Minister, Mr Ehud Barak, in the words of their most prominent slogan, "is giving away the country" to the Palestinian Authority President, Mr Yasser Arafat.
Their prospect of success: uncertain.
Yesterday's protests - which caused a degree of unease among some settlers themselves, who were reluctant to bring their children into the political fray - were prompted by Mr Barak's comment that, under a permanent peace treaty with the Palestinians, tens of thousands of settlers would be left behind to live under Palestinian rule, or invited to relocate inside sovereign Israel.
To quote from another of yesterday's posters, the settlers are trying to persuade Israelis that "you don't abandon your brothers".
To quote one of yesterday's protesters - one of the 6,000 or so settlers who live in the Gaza Strip, and who have no future there under the deal Mr Barak envisages - "the government put us in Gaza 30 years ago. They can't just say now, `We don't need you any more'."
Mr Barak's coalition is teetering on the brink of collapse, with its fate likely to be determined this week, and differences over the Palestinian peace process are a major factor. Were it to fall, opinion polls suggest that Mr Barak might nevertheless be reelected, settler complaints notwithstanding, providing that the talks stay on course.
But Israeli security officials are warning of a renewed threat of suicide attacks. The army's chief-of-staff told politicians on Sunday that a delay in negotiations could cause conflict. And Mr Arafat responded angrily by asserting that Israel was threatening violence against him.
The American peace envoy, Mr Dennis Ross, is due here later this week, to be followed by the Secretary of State, Ms Madeleine Albright, in another desperate effort to broker progress. If the talks collapse, and conflict does ensue, of course, the settlers won't need to demonstrate, because Mr Barak's peace vision will be shattered.
Meanwhile Israel is reeling from a rash of "casual" killings, six murders in three days. Mr Barak last night issued a plea to citizens not to resort to violence after murders prompted, among other things, by a row between two drivers over the right of way, a father's irritation at his baby's crying during a Euro 2000 soccer match, and an argument over deck chairs on Tel Aviv beach.
AFP adds: The UN Secretary-General, Mr Kofi Annan, flew into Beirut yesterday, and into a row over whether the Israelis had completely withdrawn from Lebanon. As he arrived, peacekeepers and Lebanese officers were checking alleged Israeli violations, three days after Mr Annan said withdrawal was complete.
And President Emile Lahoud's office said the peacekeepers should not deploy throughout the former Israeli-occupied zone until all the Israeli encroachments were resolved.
At the headquarters of the United Nations Interim Force in Lebanon (Unifil), Mr Annan said he expected its existing 4,500 soldiers to be reinforced by another 1,000 from next month.
Israel will raise its concerns with Mr Annan about the fate of Ghajar, a village on the border with Lebanon that is being chopped in two by the UN's demarcation of the frontier, a senior Israeli official said.