The pairing of Donald Trump and Elon Musk, the leader of the richest country in the world with the richest person in the world, seemed a perfect match.
But the last 10 days have seen the pair move from gentle disagreement to bitter acrimony. These are the public moments which brought their relationship crashing down.
Wednesday 28 May
Speaking to CBS News, Musk criticises Trump's plans for a new bill on tax and spending - saying the planned legislation left him "disappointed".
Trump later admits to reporters that he is "not happy about certain aspects" of the bill while at the same time being "thrilled" about some aspects, such as tax cuts.
He doesn't comment directly on Musk's remarks, however.
Thursday 29 May
Musk announces he will be leaving the Trump administration after his scheduled time as a special government employee reaches its end. He had led a cost-cutting mission known as the Department of Government Efficiency (Doge).
Friday 30 May
Trump praises Musk as the latter appears with a black eye in a press conference on his last day at the White House.
Musk is "not really leaving", the president says, and will continue to be "back and forth" to the White House.
Monday 2 June
Trump defends his "big, beautiful bill" in a post on Truth Social, claiming "many false statements" are being made about his landmark economic policy.
Tuesday 3 June
Musk again attacks Trump's planned bill, calling it "massive, outrageous, pork-filled" and "a disgusting abomination" in a post on X.
In US politics, "pork" refers to spending on projects in lawmakers' constituencies.
It marks the start of an escalation in comments from Musk on social media.
Wednesday 4 June, 13:57 local time (18:57 BST)
Musk calls for a new spending bill "that doesn't massively grow the [US government budget] deficit and increase the debt ceiling".
Wednesday 4 June, 14:50
Musk urges his followers to call their representatives to oppose Trump's bill.
Thursday 5 June, 11:20
Musk quotes a series of old post on X by Trump, from 2012 and 2013, in which Trump criticises government spending.
Thursday 5 June, 12:00
Speaking in the Oval Office alongside German Chancellor Friedrich Merz, Trump says he and Musk "had" a great relationship but "I don't know if we will anymore".
He also says Musk is "upset" that subsidies for electric vehicles would be cut in his planned bill, affecting the billionaire's Tesla and SpaceX businesses.
Thursday 5 June, 12:19
Musk responds in real-time to the broadcast from the Oval Office, dismissing Trump's assertions.
Thursday 5 June 12:24
Back at the White House, Trump tells reporters Musk knew "every aspect of the bill" and says he is "very disappointed in Elon".
Thursday 5 June, 12:25
"False," replies Musk on X. "This bill was never shown to me even once and was passed in the dead of night so fast that almost no-one in Congress would even read it!"
Thursday 5 June, 12:44
Musk resurfaces old Trump posts on X, highlighting moments when the president criticised America's budget deficits. "Where is this guy today??" he asks.
Thursday 5 June, 12:46
Replying to another user on X, Musk says: "Without me, Trump would have lost the election." He goes on to say: "Such ingratitude".
Thursday 5 June, 13:44
Still going, Musk claims on X that "the Big Ugly Bill will INCREASE the deficit to $2.5 trillion".
Thursday 5 June, 13:49
Musk continues to quote old Trump posts on X about government spending. He asks: "Where is the man who wrote these words? Was he replaced by a body double!?"
Thursday 5 June, 13:57
"Is it time to create a new political party in America that actually represents the 80% in the middle?" Musk asks in a poll on X.
Thursday 5 June, 14:37
Trump starts posting on his Truth Social platform, saying Musk had been "wearing thin" so he asked him to leave the White House, and alleging that Musk "went CRAZY".
Musk calls this "an obvious lie".
"The easiest way to save money in our Budget," Trump continues in another post, "is to terminate Elon's Governmental Subsidies and Contracts".
Thursday 5 June, 15:10
Musk alleges, without providing evidence, that Trump appears in the "Epstein files", referring to court documents and evidence collected by investigators into convicted sex offender Jeffrey Epstein.
Thursday 5 June, 16:06
Posting on Truth Social, Trump says he doesn't mind "Elon turning against me" and continues to defend his bill.
Thursday 5 June, 16:09
Responding to Trump's suggestion that he could terminate government contracts with Musk's companies, Musk says he will "immediately" decommission the Dragon spacecraft - a craft that is capable of travelling to the International Space Station.
Thursday 5 June, 16:11
Musk appears to endorse impeaching Trump while quoting a conspiracy theorist who shared his Epstein files claim about the president.
Thursday 5 June, 16:26
Musk attacks another of Trump's signature policies - his trade tariffs - by posting on X to say these "will cause a recession in the second half of this year".
Thursday 5 June, 21:27
Musk appears to soften, replying on X "you're not wrong" to another billionaire Trump backer, Bill Ackman, who had called for the pair to "make peace for the benefit of our great country".
Friday 6 June, 08:05
Trump describes Musk as "the man who has lost his mind" in an interview with ABC News and says he is "not particularly" interested in speaking to him.
The White House tells the BBC Trump does not intend to talk to the tech billionaire today, after reports they would speak on the phone later.
It is also reported by CBS, the BBC's US partner, that Trump is considering selling his Tesla car - which he had purchased when he was trying to help Musk promote his company.
