North German Confederation
According to the constitution, legislation was the matter of two organs. The Reichstag was the parliament, elected by all men above the age of 25. The Federal Council was an organ representing the governments of the states. The holder of the Bundespräsidium was the king of Prussia (the 'republican' term 'president' had been avoided intentionally). The holder of the Bundespräsidium installed the Federal Chancellor. Not by name, but factually this was the (only) federal minister, the head of the executive.