A new dawn has broken. Labour has a new leader, and the ghosts of Tony Blair and Gordon Brown are already starting to fade.

The country doesn’t know much about Ed Miliband, but that was the way with many political leaders, including David Cameron, John Major and even Margaret Thatcher when she took over the reins of the Conservative Party.

We’ll soon get used to the idea that this bright young thing is leading the Labour Party. It was clear during Labour’s Manchester conference that he was already growing into the role.

And the lack of profile will help him to push the idea of a “new generation”.

In fact, Ed Miliband was a member of the Government under both Mr Brown and Mr Blair, and a member of the cabinet for three years. He was also one of Gordon Brown’s advisers before becoming an MP.

He’s very much part of the New Labour generation, albeit as a faithful servant of Mr Blair and Brown rather than a leader.

But to those people who don’t follow politics obsessively, he will appear to be a new kid on the block.

Nobody can say he lacks courage. Taking on his older brother, who looked like a dead cert to win the leadership, proves that.

David Miliband insists he’s proud of his brother’s success, and no doubt he’s telling the truth.

But there have also been fleeting glimpses of the tension Ed’s decision to stand caused between the two of them, both during the leadership campaign and at Manchester once the result was announced.

Why should Ed step aside and fail to pursue his own ambitions, just because he happens to be the younger of the pair?

There’s no good reason. But families don’t work like that.

In practice, what he did was both bold and brutal.

And Ed Miliband has shown exactly the same approach in turning on Labour’s former leaders, Tony Blair, the election-winning machine, and Gordon Brown, Mr Miliband’s former friend and mentor. In attacking their policies during his conference speech, and mocking Mr Brown’s claim to have ended “boom and bust”, he successfully drew a line under the “new Labour” era.

There’s no question of former leaders becoming back-seat drivers in Mr Miliband’s reign. He effectively consigned them to the dustbin of history.

What does this mean for David Cameron, in Birmingham for his own party conference?

The Conservative leader is set to experience something he hasn’t known since he became Prime Minister – opposition.

With the Liberal Democrats in the Coalition, Labour is the only major opposition party.

But it hasn’t done much opposing. Acting leader Harriet Harman was effective in the House of Commons and Shadow Education Secretary Ed Balls took the fight to the Tories over school building projects, but the party’s attention was understandably focused on the leadership campaign.

With Mr Miliband at the helm, that will change.

It’s possible that Labour will let the Conservatives enjoy their week in the sun as they descend on Birmingham, but once Parliament resumes sitting the gloves will be off. October 20 is the date to watch, as this is when the Coalition will reveal how much exactly they plan to cut public spending by - and which departments face the knife.

It is when the Coalition will demonstrate whether or not it has the courage to make the cuts that are needed and to explain itself to the public.

But it is also when Labour (and its union friends) will learn whether they made the right decision in rejecting David and choosing brother Ed instead.