What is the breakthrough/discovery used for?

the pogroms became known as kristallnacht, the "night of shattered glass," for the shattered glass from the store windows that littered the streets. the morning after the pogroms 30,000 german jewish men were arrested for the "crime" of being jewish and sent to concentration camps, where hundreds of them perished.

hello,

what started the norman conquest?

profound political, administrative, and social changes in the british isles. last line of my information: )