Simplify the following text for a Grade 8 native English-speaking person.
Original: In English the ( untranslated ) word `` Kaiser '' is mainly associated with the emperors of the unified German Empire ( 1871 â `` 1918 ) , in particular with Kaiser Wilhelm II , and with the emperors of Austria-Hungary , in particular with Kaiser Franz Joseph I.
Simplified: Kaiser was title used for the Emperor of Germany from the creation of unified Germany in 1871 until the end of World War I. The word `` Kaiser '' is the German word for Caesar , the name the ancient Romans used for their emperor .