Which event happened before Barbara leaned out her window-sill?

wwii

explanation:

ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.

napoleon the third became a empire in 1873 also known as the era of the franco-prussian war.