NPR and BBC both report imperialist talking points of their respective governments as fact without the slightest hint of criticism.
Far left would be Democracy Now, Jacobin, Mother Jones, The Nation, etc.
At Media Bias/Fact Check, Democracy Now and The Nation are reported "Left", Mother Jones is on the far side of "Left-Center" and Jacobin is assessed as slightly left of "Left".
All are considered to have "High" factuality. I personally agree with these assessments, for what it's worth.
The BBC is vocally critical of imperialism[0], at least on a surface level. I always considered their opinion pieces centre-left (e.g. "bootlicking apologists" rather than "hidebound reactionaries") even when I was on the far left running around with wannabe revolutionary socialists.
When it comes to that, the WSJ news section is arguably closer to centre-right than AP or Reuters. I think there are a microcosm of tiny complexities within the categories.
> The BBC is vocally critical of imperialism[0], at least on a surface level.
I'm not sure that's a left/right issue, unless it happens to be the 1950s (there are some surviving imperialists on the right, and ~none on the left, but I wouldn't expect the _average_ Tory voter to be too gung-ho about how great the empire was...)
Also, that site is a GCSE revision site; I think that's just the history curriculum. And nothing seems particularly over-critical on the page you linked.
As the sibling comment says, the bitesize revision is based on the National Curriculum: i.e. it's the state's own version of its history. Not exactly a hotbed of radicalism.