Time line/ mention of previous characters

[Ali]

OK what is the time line here?
did the Union declare war on Black daw as soon as he did the coup?
or did they wait!? because the time frame doesn't fit..
did the war last 10 years ? or did they wait most of the these years not attacking!?

2- Why is no one mentioning the demon Ferrnis the feared. not even once! it's like everyone had their memory wiped out in that regard!