#OnThisDay 1915 The RMS Lusitania was torpedoed by U-20 (which initially took Casement to Ireland) 10 miles off the Irish coast, killing 1,198 people. She was carrying millions of rounds of ammo & other war materiel, which made her a valid military target, despite what the British authorities said she was holding in her cargo hold.
Over a hundred of the deceased were American citizens and this was one of the reasons used to get the US to join the Allies in the First World War.
This pressure brought a temporary end to Germany’s unrestricted submarine warfare. It was used to boost recruitment in Ireland, USA and Britain too.