Rule by decree is a style of governance allowing quick, unchallenged promulgation of law by a single person or group of people, usually without legislative approval. While intended to allow rapid responses to a crisis, rule by decree is easily abused and is often a key feature of dictatorships.
When a state of emergency, such as martial law, is in place, rule by decree is common. While rule by decree is easily susceptible to the whims and corruption of the person in power, it is also highly efficient: a law can take weeks or months to pass in a legislature, but can be edited quickly during ruling by decree. This is what makes it valuable in emergency situations. Thus, it is allowed by many constitutions, including the French, Argentine, Indian and Hungarian constitutions.
The expression is also sometimes used when describing actions of democratic governments that are perceived to unduly bypass scrutiny from the legislature or populace.
One of the first examples of rule by decree was in the ancient Roman Republic, after the assassination of Julius Caesar in 44 BC, his successor Gaius Octavian (Augustus), general Mark Antony and succeeding pontifex maximus Aemilius Lepidus seized power in the Second Triumvirate, officially recognized by the senate by the Lex Titia decree. The resolution, which gave the three 'triumvirs' authoritarian powers for five years, was enacted and reinstated consecutive in 38 BC. It finally collapsed in 33/32 BC, after the downfall of Lepidus, leading to the final Roman Republican civil war and the total collapse of republican government.
The most prominent example in history is the Reichstag Fire Decree in Germany, passed after the Reichstag building caught fire in 1933. German Chancellor Adolf Hitler convinced President Paul von Hindenburg to invoke Article 48 of the Weimar Constitution and issue a decree suspending basic civil rights indefinitely. As a result of this decree, German authorities were able to constitutionally suppress or imprison their opposition, which in turn paved the way for the one-party rule of the Nazi Party.