Q:

Meaning of the sentence "...had expected to behold her dimmed and obscured by a disastrous cloud..."

I'm unable to understand this long sentence, particularly the parts highlighted in bold. Can someone break it up for me?

Those who had before known her, (1) and had expected to behold her dimmed and obscured by a disastrous cloud, were astonished, and even startled, (2) to perceive how her beauty shone out, and made a halo of the misfortune and ignominy in which she was enveloped.

A:

Here it is in several sentences:

Some people had known her before. They expected that she would have a horrible cloud around her that would dim and obscure her. What actually happened was that her beauty shone out. It even made a halo from the misfortune and ignominy (disgrace) around her. This astonished and even startled them.

This is a metaphor, of course. Nobody expected a genuine cloud with rain around her. Her beauty didn't literally emit light, nor did she have a halo as in religious pictures, and the halo she didn't have wasn't made of misery. But metaphorically they expected her to have done terribly and to be miserable and ugly, but instead she was beautiful and happy and admirable.
This is reminding me of What Katy Did and other books of that era, which I generally detest as an adult precisely for sentences like that, both their construction and meaning, but that is just an aside.

A:

With these long sentences common in Classics you might find it useful to understand the meaning by working backwards from the end of the paragraph. Modern English is very 'up front' in that it likes to put the most important information near the beginning of the sentence/paragraph and the 'fluff' at the end.
This was not the case previously and the language was heavily-influenced by other European languages where writers spoke multiple languages and wanted to make their ideas as 'fancy' as possible.
So here is your paragraph 'backwards':

She was enveloped in misfortune and ignominy. Despite this her beauty
  shone out like a halo. Many who had known her were astonished and
  startled to perceive this. They had expected her to be dimmed and
  obscured by a disastrous cloud.

