He was the reluctant employee from the beginning. The story goes the Exxon Oil chief was nearing retirement and looking forward to some well-earned 'me' time.
So when the offer to be secretary of state came he was inclined to say, "Thanks but no thanks". It was his wife, we're told, who insisted he should do it, for the country.
Almost from day one it was clear this was not a match made in heaven.
The President and Secretary of State had very different world views.
Like Donald Trump, Rex Tillerson was a wealthy businessman and a consummate deal maker.
But he did not have the impulsive gut-led instincts his boss does and that led to disagreements and humiliations.
Mr Tillerson was a facilitator, a persuader, not a disruptor.
The differences in substance and style were defined almost from the very start of the administration.
When Mr Trump ordered the US out of the Paris Climate Agreement, Mr Tillerson thought it was a mistake, and said so.
The two men were split on the key issue of Iran's nuclear agreement, with Mr Trump describing it as one of the worst deals he'd ever seen.
At the same time, Mr Tillerson had been urging his President to ratify the deal.
The now-sacked Secretary of State had asked Mr Trump to calm fears among NATO allies that he would reaffirm the principle of common defence, something the President refused to do.
And on North Korea, the two men were constantly contradicting one another.
When Donald Trump tweeted there could be no deals with North Korea last year, Mr Tillerson said negotiations were always an option.
And when just last week it was revealed the President would meet with Kim Jong-un, he not only didn't consult with his chief diplomat, he didn't even tell him he was going to do it.
And that came a day after Mr Tillerson had said there was little chance of talks between the two leaders.
But perhaps Mr Tillerson's greatest sin was his reported description of Mr Trump at a private gathering as a 'moron'.
That was never going to please a man who describes himself as a 'genius'.
Sacked on Twitter
The manner of his departure says it all.
Media reports say Mr Trump told his chief of staff John Kelly to call Mr Tillerson last Friday to let him know his services were to be terminated.
Exactly when, he couldn't say.
If the Secretary of State wanted the privilege of jumping before being pushed, he wasn't quick enough.
He found out when we did, via a Trump Tweet.
Like a failed contestant in Mr Trump's TV hit, The Apprentice, he got the simple message: "You're Fired."
His sacking may come as a blessed relief for the fading face of US diplomacy.
The wonder is he lasted so long.
Many of the Trump inner circle had been excised long before Mr Tillerson.
Just a few faces remain from the originals, including the key 'calm' Defence Secretary, Jim Mattis.
Do these departures unsettle the President? Do they tell him something is seriously wrong with his administration?
If he is rattled, he hides it well. Just a few days ago he said chaos was good.
By that definition, these are great times.
Mr Tillerson may not share that view. But from now on, his opinions are from the sidelines. Another 'former' Trump trustee.
His replacement, CIA director Mike Pompeo, is a better ideological fit for the President.
The role of secretary of state is a tricky one under Mr Trump, where months of careful diplomacy can be disrupted with a single late-night tweet.
But ultimately, there is only room for one boss.
Disagree with him and you too may receive full and frank career advice, via Twitter of course.
Tillerson will not be the last to go.