Sajid Javid disowned Theresa May's pledge to create a "hostile environment" for illegal immigrants as he vowed to put his own stamp on government policy as Home Secretary.
In a resignation letter to Mrs May, Amber Rudd said that she had inadvertently misled a parliamentary committee last Wednesday by denying that the government had targets for the deportation of illegal migrants.
Laura Kuenssberg, the BBC's political editor, avoided saying Rudd had not been entirely truthful but put the matter quite elegantly: "Certainly there has been a mismatch between what she told MPs last week and the evidence that emerged".
His appointment is also a landmark: he is the first politician from an ethnic minority to take on one of the great offices of state - the biggest jobs in cabinet.
She originally told the Home Affairs Committee no such targets existed, before being forced to row back and then scrap the regional targets held by immigration enforcement officials. May's record stay in the Home Office between 2010 and 2016 compared to her successor's fairly typical two years is somewhat ironic considering that it was arguably May's fondness for immigration targets which in part laid the foundations for Rudd's undoing. Rudd's relatively short tenure at the Home Office is not untypical for that department.
Labour's foreign affairs spokeswoman Emily Thornberry said on a visit to Ramallah: "If we are looking for who is culpable it isn't just Amber Rudd - obviously it is her leader as well".
But moving Sajid Javid in, after Amber Rudd took herself out, does not end the prime minister's problems.
Javid repeatedly referred to himself as a "second-generation migrant" as he claimed he was "personally committed and invested" in setting right the procedures which saw people who had lived in the United Kingdom all their adult lives face deportation.
Rudd's departure from the government is a massive blow to May, who was her immediate predecessor in the Home Office.
The concern for Brexit supporters is that she could join a bloc of pro-European rebels in parliament during key Brexit votes, setting up possible defeats on issues such as the government's plan not to join a customs union with the EU.
The Windrush scandal, said Rob Ford, a professor of politics at the University of Manchester, "highlights that, even with all of the toxic politics we've had around immigration in the country for well over a decade, there is a basic kind of gut-level sense of fair treatment and fair play".
"I'm very proud that's happened".
May will look to Javid, known for his passion for detail when business minister, to put a stop to what has been an nearly continual drip-feed of criticism of the ministry.
Rudd was a strong supporter for staying in the bloc, and Javid will now replace her on key cabinet committees that will help decide the future of Britain's relationship with the European Union ahead of Brexit day in March 2019.
Brokenshire served as immigration minister when May was home secretary.
The home secretary's offence was in pursuing what nearly amounted to a policy of ethnic cleansing.
Rudd's fall and Javid's elevation has further damaged the gender balance of May's cabinet, however, although in the context of the scandal that led to this change that is probably not going to make significant waves.
Javid's appointment was applauded by his Conservative colleagues, with chief secretary to the Treasury Liz Truss praising him as "effective, no-nonsense and brave", while former minister Nick Boles said he was "proud to be a colleague" of the UK's first home secretary from a Muslim background.