After the end of Imperial Germany, Weimar Germany decided to install a president instead of the kaiser. (In fact, the term Ersatzkaiser was often used.) While not carrying as much power as the American presidents (the Weimar presidents didn't do the actual government work, that's what The Chancellors of Germany had to do), as the supreme commander of the armed forces and the man who could appoint and fire governments at will, they were still pretty powerful. After the bad experiences with strong presidents, the constitution of West Germany gave most power to the chancellor and made the president a purely ceremonial head of state. Still, some presidents could take a bit of influence thanks to personal charisma.
Paul von Hindenburg, former World War One marshal — no party, closest to the conservative German nationalists. Became the candidate for the right-wing parties in the second round of voting and defeated the democratic candidate, former chancellor Wilhelm Marx (not related). Hindenburg also won because the Communists would rather vote for their own candidate instead for Marx, splitting the anti-Hindenburg vote, and because the Bavarian Catholics supported the Protestant Prussian over the Catholic Rhinelander Marx (oh the irony). Although he didn't like the republic much, being a traditional monarchist, he still swore an oath on the constitution. He was already 77 years old when elected for the first time, thus making him 84 when reelected in 1932. However, at that time he was seen as the only one who could prevent a certain guy from Austria becoming president instead. And one year later, he appointed him chancellor. Another year later, he died, and Hitler had absolute power.
Adolf Hitler — National Socialist. Hitler absorbed the state office of President during his tenure as leader of the Third Reich, but he didn't actually use the title. Officially out of respect for Hindenburg, unofficially because it was a democratic institution and too reminiscent of the "heriditary" arch-enemy France. Hitler created a new office and combined it with his chancellor office, creating the combined office of Führer und Reichskanzler, representing Hitler's dual roles as Chief of State and Chief of Government. Technically Hitler had a third role as Führer of the Nazi Party, but the relationship between the Party, the State and the Government was very confusing in the Third Reich (and that's leaving out the military offices Hitler also acquired). In practice Hitler was simply the Leader, no qualification required. Fun fact: Being born Austrian, he got the German citizenship relatively late, otherwise he wouldn't have been electable at all.
Karl Dönitz — National Socialist. Supreme commander of Germany's submarines before. Hitler decreed before his death that his office would be broken up into a presidential office and a chancellor office again, and Dönitz was handed the Presidential one. Hadn't really much to do after Hitler's suicide and signed Germany's capitulation in May 1945. Was arrested by the Allies, brought to court in Nuremberg and served 10 years in Spandau, together with guys like Albert Speer and Rudolf Hess (Göring having committed suicide in Nuremberg.)
Presidents of post-war Germany:
Theodor Heuss — Liberal Democrat. A jovial guy who liked humor and wine. Tried to keep party politics out of his office. Started the first Arbor Day in Germany. Albert Schweitzer was the pastor at Heuss' wedding; Heuss' wife was a personal friend of Schweitzer's.
Heinrich Lübke — Christian Democrat. Became infamous for his broken English and various goofs, some of which became Memetic Mutation. While some of them may have been invented, it is true frex that on a visit in Madagascar, he greeted the president with "Dear Mr president, dear Mrs Tananarive..." (Tananarive being Madagascar's capital!) For some reason, Penfold from Danger Mouse was named Lübke in the German translation.
Gustav Heinemann — Social Democrat. Originally a member of the Christian Democrats which he left when Adenauer started to rearm West Germany. He founded the small GVP, which later joined the Social Democrats. Narrowly elected by Liberal and Social Democrats, the latter still being in a grand coalition with the Christian Democrats. Once when asked whether he'd love Germany, he answered "I don't love the state, I love my wife." Generally, a quiet guy. Only served one term, for health and age reasons.
Karl Carstens — Christian Democrat. His election was an alarm sign for the social-liberal coalition which had been weakened in the länder. Somewhat controversial for having been a member of the nazi party. Liked hiking and used this hobby to "meet the German people". Only served one term, feeling to old for a second one.
Richard von Weizsäcker — Christian Democrat. Former grand mayor of West Berlin. Compared to "a mixture of banker and church congress president". Proved to be very popular among all democratic parties, even the Greens, and was reelected unopposed. Presided during the reunification of Germany.
Roman Herzog — Christian Democrat. Former head of the German Supreme Court. Became the candidate after Helmut Kohl's candidate Steffen Heitmann (who'd have been the first president from East Germany in The Berlin Republic) proved to be too conservative. Took three rounds to be elected, but he proved to be quite popular. Most famous for his "Ruck-Rede" (roughly: tug speech), criticizing the Germans for being too indolent.
Johannes Rau — Social Democrat. Grandson-in-law of his predecessor Gustav Heinemann, in fact. And like him, a former member of the GVP. (His opponent from the Left Party was his wife's aunt - how ironic.) First German politician to speak in the Knesset, the parliament of Israel.
Horst Köhler — Christian Democrat. Former head of the IMF (International Monetary Fund).note A position reserved for Europeans despite the Washington, DC HQ, and an excellent shortcut to respectability; former IMF head Dominique Strauss-Kahn was launching a Presidential bid in France for much the same reason, and it seemed to be working: he seemed to be the only Socialist candidate consistently capable of beating the Sarkodile - but you know the rest. First president who wasn't a politician. Reelected in 2009, but quit just one year later after some remarks he made about the military's role became hugely controversial - the first president to do so.
Christian Wulff — Christian Democrat. Former minister president of Lower Saxony. He was accused of getting a loan from a businessman for better conditions, which tripped an avalanche of other accusations. When it got so bad that he might have lost his immunity, he abdicated after less than two years in office.
Joachim Gauck — Independent. Former Lutheran pastor from East Germanynote which means that currently the head of state and the head of government are former GDR citizens, who appeared on the political stage during the time of the Hole in Flag revolutions. After the fall of the Berlin Wall, he was the head of the government agency responsible for investigating the crimes of The Stasi (the GDR's infamous Secret Police).
East Germany had a president until 1960 (only one office-holder, Wilhelm Pieck), then replaced that office with a collective council of state, which had a chairman.