This is just my impression. Jane Austen is parodying Goldsmith's, the standard history text of her time.

History, particularly in JA's time was treated very seriously. It is considered to embody English culture and memory. However, according to JulieW's posts below Goldsmith's was rather sloppy in it's approach. It had few dates and like other schoolchildren she found it ponderous and boring to toil through it's four volumes.

There is an interesting converstion in Northanger Abbey between Catherine Morland and Henry Tilney, ch.14
Henry gives one of his clever comments;

'That little girls and boys should be so tormented, is what noone at all acquainted with human nature can deny; but in behalf of our most distinguished historians, I must observe, that
they might be offended at being supposed to have no higher aim;...I use the verb "to torment", as I have observed to be your own method, instead of "to instruct", supposing them to be now admitted as synonymous'.

I think by Henry's comment, Austen means historians make the subject an absolute pain even if not their intention.

I'm unsure if the Lancastrian/Yorkist debate figured much in JA's time, at least politically. I'm inclined to think it was carried on in academic circles.

*However, I have read the politican Horace Walpole queried the the blackened reputation of a Yorkist king who is coming up tomorrow.

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