The leaders met in a Bedouin tent outside Tripoli
Tony Blair is back in Britain after the EU summit in Brussels and his historic meeting with Colonel Gaddafi in Libya. On Tuesday he attended the Spanish state memorial service for the victims of the Madrid train bombs, before travelling on to Portugal. The BBC's Political Editor Andrew Marr was with him, recording events as they happen.
En route to London :: 1600GMT
It had been, even by his standards, a daunting week.
The Libyan visit was set up on Monday.
Between Tuesday and Friday morning, Tony Blair had packed in talks in Northern Ireland.
Then he met the new Spanish prime minister before attending the Madrid funeral.
He made a plangent, thoughtful speech on terrorism in Portugal, then went to meet Gadaffi in his tent outside Tripoli.
Finally he swept back again for talks on the EU's new constitution (it's on again) in Brussels.
He looked tired, but that's hardly surprising.
What must it have been like, moving from the solemn Spanish mourning, surrounded by people who suspected the war he started had been part of the reason for the deaths of more than 200 people, to meeting Gadaffi, whose agents killed 270 people at Lockerbie, and shaking his hand?
Did the Prime Minister feel queasy? Or morally uncertain about it all?
We can guess, and record his self-certain public statements, but that's all.
In the old days, when lobby journalists travelled with Mr Blair in his plane, chartered from British Airways, he would make a point of coming back for private off-the-record chats, filling us in with his less public speculations and feeding titbits of information - the "colour" of what Putin actually seemed like, close-to, or what dinner with Bush had been like.
Not any more.
He was as cut-off and closed-up as a very shy clam.
This has probably happened as a result of his notorious trip to the Far East last year when he was surrounded on the plane by reporters determined to find out whether he did, or did not, authorise the naming of David Kelly.
His answer became a major political story and was pored over for months. It seems that he has decided informal chats with hacks are just too dangerous now, for too little benefit.
We can understand why; but it is another moment when power isolates itself, pulling back to its innermost thoughts.
It was a momentous week, and an exciting one to cover; but there was something slightly sad about it too.
Brussels :: 1230 GMT
In so many ways it was a mad, mad week - madder than some of the Blair whirlwind mystery tours after September 11 - Belfast, Madrid, Lisbon, Tripoli and Brussels in three days.
"You look knackered," said Gaddafi when Blair finally arrived in his tent - or Arabic words to that effect.
Emotionally it must have been draining - the poignant grandeur of the state funeral for the victims, and how must it have felt to be surrounded by people who felt the victims died partly because of a war he helped to start?
He had the air of a man who realised just how much political damage Iraq had caused him - if so it was a rare reflective moment.
Blair looks not exhausted - but grim, subdued, older.
I don't think he enjoyed what he had to do this week - I hope he didn't - but it's clear just how much he hates being constantly being surrounded by journalists, lenses and questions.
Gaddafi's camels have their flies - he has us.
Brussels :: 2200GMT
Tony Blair, still having dinner, has got some great after-dinner tales to tell, I would have thought. Apart from the fairly bizarre nature of meeting in the tents, surrounded by camels, there was some very serious talking going on.
And on al-Qaeda, a message from the Libyans that Tony Blair really wanted to hear.
The Libyan foreign minister said `We can't stand al-Qaeda, they're bad for our region, they're bad for our prosperity, they're bad for our culture, they're bad for our future, they're bad for our women too.'
That is the kind of thing Tony Blair wanted to hear.
But of course, the small talk, the atmosphere, was as interesting to a lot of people as well.
They sat round discussing their mutual political systems, as leaders left to themselves tend to do.
At one point Colonel Gaddafi said: 'We have a very simple system in Libya. We have a very open, democratic system - it's like a great big circle, and there in the middle is me.'
Tony Blair's reaction to this is not recorded.
Brussels :: 1810GMT
If we're talking about achievement, then this is mostly symbolic. Let's remember that although Colonel Gaddafi would have liked to have had nuclear weapons, he never possessed them.
Western intelligence agencies hope that the Libyans can help in the hunt for Al-Qaeda and that's important.
But I think the most important thing of all is that Colonel Gaddafi who for nearly 40 years has been a leading symbol of the fight against the West, a consistent supporter of terrorism, has now in effect, held his hands up and joined the rest of the world.
It's not surrender, it's not as brutal as that.
But it was important that Mr Gaddafi in his conversation said that he believed Al Qaeda is almost as much of a threat to them as to the West.
He said they were bad news for the Libyan economy, bad news for progress, bad news for their culture, and bad news for their women.
And that's what Mr Blair wanted to hear.
That doesn't mean that absolutely anyone can now be Tony Blair's friend.
But frankly after this day, any leader involved in terrorism who then renounces it, can expect to be brought in with both hands by the West.
Tripoli :: 1310GMT
The meeting seems to have been remarkably cordial.
Gaddafi is a rather charismatic figure, given to joking, and quickly the two were exchanging jokes about the quality of the British press.
There was hard talking done and much agreement on terrorism, and of course those hard cash deals, always part of such an occasion.
This gamble has paid off in the short term - Blair has not been greatly embarrassed. There's been a lot of careful choreography and extraordinary shots of camels and tents which will go around the world.
This a coup for Gaddafi and for Blair.
But we haven't seen Gaddafi live in front of the cameras and that's not a surprise or a mistake.
Tripoli :: 1105GMT
Never did we expect this moment - Tony Blair arriving to meet the man who until recently was seen as a godfather of international terrorism.
The scene here is completely extraordinary, quite surreal.
In some ways this looks like Lincolnshire, but there are camels and security people all around me, and of course in that tent Colonel Gaddafi is sitting down talking turkey with Tony Blair.
His first words to the prime minister were: "You seem exhausted," to which if he'd replied honestly Tony Blair probably would have said: "No no, just a little uneasy."
Gaddafi then remarked that he looked quite young and fit - you wouldn't have guessed that if you read the British press.
This is an absolutely pivotal moment in the history of this region and possibly even in the war against terrorism, because Libya has renounced its weapons of mass destruction programmes and in return there will be a great sluice of western investment going into this country.
Among the deals we expect to be announced shortly are ones involving Shell and British Aerospace, worth ultimately over $1bn.
Some will find this meeting unsavoury - but it is an historic and extraordinary moment.
But with the wild smell of wild thyme and couscous for lunch this felt almost banal - like a roadside picnic in an English field.
En route to Tripoli :: 0810GMT
Just how much of a risk is Tony Blair taking when he sits down in a tent later to talk and listen to Colonel Muammar Gaddafi, that idiosyncratic revolutionary who came to power when Mr Blair was still at school?
The Libyan leader was later condemned as the inspiration behind numerous terrorist acts, most notoriously Lockerbie, and denounced by US President Ronald Reagan as the mad dog of the Middle East.
Odd though it may seem the political risk for Mr Blair in meeting Gaddafi is not enormous.
Libya has paid most of its outstanding debts over Lockerbie. It has compensated the families, accepted general responsibility for the murder of WPC Yvonne Fletcher and only this month shipped its technology set aside for its Weapons of Mass Destruction programme to the US for destruction.
Libya has made an unalterable turn towards its old enemies of bourgeois Western democracy.
Whatever the reasons for this, the course is pretty clear.
But there is still a high risk of personal embarrassment for Mr Blair - Gaddafi remains a most unpredictable man, who not so long ago was still advocating the bombing of London and more recently hailed Tony Benn as Labour's spiritual leader.
When I asked Tony Blair about the risk he was taking, he replied in effect that it was worth it.
But he paused for a very long time first.
Lisbon :: 2200GMT
Wednesday was a pretty significant and extraordinary day for Tony Blair. He
started off at a memorial surrounded by a crowd who thought the people died partly because of war he started.
He wasn't apologetic, I thought -
but there was certainly an element of self doubt there.
In a brief speech - which was really only meant to be a few remarks - in the garden of the Portuguese prime minister's house, he started off by saying 'Look, I understand that those people who think I messed up the war on terrorism by what I did in Iraq are as passionate as I am and we're never going to resolve this, perhaps not now, perhaps not ever. Please, let's move on.'
I just got the sense that for the first time this was a prime minister - not who thought that he was wrong about Iraq - but who had come to an understanding of just how much political damage Iraq has done him.
Moving on to Libya, Mr Blair is not taking a great deal of risk. Libya is not going to suddenly turn tail and take up international terrorism again. It has made that change.
But when it comes to personal risk, there is quite a lot. Colonel Gaddafi is an extremely unpredictable character, who says very, very odd things from time to time.
Lisbon :: 1805GMT
Tony Blair has been trying to explain why he can do a deal with Colonel Gaddafi, memorably described by Ronald Reagan as the "mad dog of the Middle East", but he can't do any deal, ever, with al-Qaeda.
The argument he's just been making is that when it comes to Islamic fanatics, there is no kind of demand that you can negotiate about.
So according to him, you can not negotiate, you simply have to fight them, or live under the climate of fear that they create.
He's trying to say that on the one hand there are people like the Libyan leader who you can eventually do some kind of a deal with.
But don't assume that doing a deal with former terrorists like Gaddafi means that one day they can do a deal with al-Qaeda.
The political risks are serious. We know what Gaddafi's strategy is, but you never know what he's going to say next.
He's talked in the past about dealing with terrorism by bombing London.
Now Tony Blair is going to sit down with him in a tent in Tripoli tomorrow, and frankly, he'll have no idea what the Libyan leader is going to say.
They will probably keep the cameras and the press away from that meeting and they're probably right to do so.
Almudena Cathedral, Madrid :: 1200GMT
The terrible truth is that no journalist really knows what goes on during these whirlwind diplomatic tours.
All we saw of Tony Blair and Spain's next prime minister Jose Luis Zapatero was an uncomfortable rictus of mimicked geniality for the cameras, before they disappeared into their private meeting.
Tony Blair had dinner with the outgoing Spanish prime minister
This meeting was so private that, for the crucial part, when they discussed the Spanish Socialists' highly uncomplimentary view on Mr Blair and the Iraq war, no officials were present.
What we know for sure is that Mr Blair failed to persuade Mr Zapatero to keep Spanish troops in Iraq.
He cannot have been surprised by that since withdrawing them was a major election pledge by the Spanish Socialists.
They will meet again in London once Mr Zapatero has formally become prime minister.
Will these two relatively young leaders manage a decent relationship? The answer is probably yes, if only because they are more or less fated to.
Political friendships are friendships of necessity, like arranged marriages.
And, just like arranged marriages, outsiders have little idea what really goes on when the door is closed.
Congresso Delos Deputados, Madrid :: 0810GMT
Tony and Cherie Blair were welcomed last night in Madrid by the outgoing prime minister, Jose Maria Aznar. They had a friendly dinner together but perhaps what was really on Blair's mind was today's meeting with the next Spanish leader.
Fresh-faced, a family man and with a legal background, Jose Luis Rodriguez Zapatero may remind Tony Blair of his younger self.
He's also a man of the moderate Left, though he talks about the New Way, not Blair's Third Way.
Mr Zapatero looks like unmitigated bad news for Tony Blair.
Not only have his Spanish socialists won on the back of huge public anger about the Iraq war and the Madrid bombings but he doesn't seem to be a man who minces his words.
The leaders met in a Bedouin tent outside Tripoli
The body language will be fascinating, the conversation even more so - which is why journalists are being kept well away.
This is only the start of a week of difficult diplomacy for Mr Blair and Mr Zapatero is not likely to be the hardest nut.
The diplomatic world believes that Libya's Colonel Gaddafi will be dropped in on too.
So the mood here is edgy, a little brittle.
Mostly on these trips Mr Blair demonstrates just how relaxed he is by ambling to the back of his aeroplane to chew the fat with the hacks.
So far, no amble and that perhaps is all you really need to know.