April 12 in History

Shapur I also known as Shapur I the Great was the second Sasanian King of Kings of Iran. The precise dating of his reign is disputed, but it is generally agreed that he ruled from 240 to 270, with his father Ardashir I as co-regent until the death of the latter in 242. During his co-regency, he helped his father with the conquest and destruction of the city of Hatra, whose fall was facilitated, according to the Islamic myth, by the actions of his future wife al-Nadirah. Shapur also consolidated and expanded the empire of Ardashir I, waged war against the Roman Empire, and seized its cities of Nisibis and Carrhae while he was advancing as far as Roman Syria. Although he was defeated at the Battle of Resaena in 243 by Roman emperor Gordian III, the following year he was able to win the Battle of Misiche and force the new Roman emperor Philip the Arab to sign a favorable peace treaty that was regarded by the Romans as "a most shameful treaty".

Edwin, also known as Eadwine or Æduinus, was the King of Deira and Bernicia – which later became known as Northumbria – from around 616 until his death. He was the second monarch to rule both of these northern English kingdoms and the first to convert to Christianity. After he died in battle, he was venerated as a saint.

Prince of Antioch was the title given during the Middle Ages to Norman rulers of the Principality of Antioch, a region surrounding the city of Antioch. The Princes originally came from the County of Sicily. Prince Bohemond IV of Antioch additionally came into possession of the County of Tripoli, combining these two Crusader states for the rest of their histories.

In the history of the Netherlands, the instruction of 12 April 1588 is a decision of the States General of the Netherlands passed on 12 April 1588 during the Eighty Years' War. It transferred the duties of the executive branch of government from the landvoogd to the Council of State. In conjunction with a separate decision taken by the States General to transfer the oaths of allegiance of all officials from Leicester to themselves on the same day, the instruction is widely regarded as the formal establishment of the Dutch Republic.

The American Revolution (1765–1783) was a political movement in the Thirteen Colonies of Great Britain and the United States which the colonies founded. The movement began as a rebellion demanding reform and evolved into a revolution resulting in a complete separation that entirely replaced the social and political order. These changes were the outcome of the associated American Revolutionary War and the consequential sovereign independence of the former colonies as the United States. The Second Continental Congress, as the provisional government, established the Continental Army and appointed George Washington as its commander-in-chief in 1775. The following year, the Congress unanimously adopted the Declaration of Independence on the Fourth of July. Throughout most of the war, the outcome appeared uncertain. However, in 1781, a decisive victory by Washington and the Continental Army in the Siege of Yorktown led King George III and the Fox–North coalition in government to negotiate the cessation of colonial rule and the acknowledgment of American sovereignty, formalized in the Treaty of Paris in 1783. The Constitution took effect in 1789 and the Bill of Rights was ratified in 1791.