Kaisers of Austria-Hungary/Danubia
Karl I (1887 - 1959, r. 1916 - 1959)
Karl I became kaiser midst of First Weltkrieg. He tried several times reform Austria-Hungary but Hungarians didn't accept plans for federalisations until 1937 Aungsleich where the kaiser finally managed push his plans for full federalisation of the empire. Austria-Hungary officially became Danubian federation in 1938 when new federal constitution was passed.
Karl I had important role on early stages of Second Weltkrieg. When Socialist Republic of Italy invaded Papal States on October 1940 and killed pope Pius XII, the kaiser managed rise lot of Danubians prepare to the conflict with Italy. On early days of January 1941 Danubia became participant of WK2 when Romania, Serbia and SRI invaded the country. With Gemran help Danubia anyway managed to win the war.
Danubian Federation recovered from the war quiet well, atlough there was some nationalist restless. But in 1950's these became really bad in Bosnia and next decades would are known as Bosnian Troubles. But economy still boosted rapidly and cultural life begun to rise. Danubia became one of most notable film industrial nations in Europe. Karl I was pretty popular around the empire. He died from sudden heart attack in 1959. He was conines by pope in 2017 being one of few monarchs of 20th century who were canonised by Catholic Church.
Otto (1912 - 2011, r. 1959 - 2011)
Already as archduke and crown prince Otto had several diplomacy activities. During Second Weltkrieg he served briefly on Italian front altough wasn't anywhere close of actual combat regions.
Otto became kaiser after his father's death. His reign saw massive liberilisation on society and political refortms. Danubia remained quiet stable but Bosnia was long-time headache for several chancellors of the empire. Otto supported further integration of Mitteleuropa. Danubia had good relationships with its neighbors and remained loyal ally of Germany. But relationships with Serbia were sometimes really bad. The kaiser too tried many times push peace process in Bosnia but there was markable reuslts only just in 1990's and finally peace agreement in 1999.
Karl II (b. 1944 r. 2011 - )
Karl was born midst of Second Weltkrieg to archduke, future Kaiser Otto and archduchess Irmingard of Bavaria, daughter of Rupprecht, king of Bavaria. During his youth years Karl was educated in universities of Vienna, Prague Budapest, Zagreb and in some other important places of the empire and was educated to speak fluent Hungarian, Czechian, Polish and Croatian. In 1970 he married woman from low-nobility Hungarian family. Kaiser Otto accepted that and changed rules so that royal marriages are not required.
In 2011 Karl became kaiser after death of Otto. He has managed to keep the multinational empire together altough he is not quiet that popular as his father.