They had split from the Social Democratic Party, which capitulated to nationalism and backed the war and the German war effort, and they had formed the Spartacus League in January of 1916.
50 years later East Germany released a stamp set to commemorate them and their bravery.
Both went on to participate in the founding of the Communist Party of Germany on December 30, 1918. A mere fortnight later both were murdered by the authorities after an abortive uprising.
Karl Liebknecht's final cry for a better tomorrow, written on the very day of his death, still rings out today, despite all the detours, defeats, setbacks and disillusionments of the last hundred years.
It is never too late to write the future!