During the medieval period, any provincial governor of a sovereign state could make a unilateral declaration of independence (UDI) and become the ruler of an independent and separate state provided he could stay in power and resist possible attacks by the central authority or other invaders. Those days are gone. If we look at recent history of UDIs, we observe a different pattern.
In the case of the United States of America, it was not an individual who made the declaration. The Congress adopted the declaration on July 4, 1776. George Washington, who was fighting a revolutionary war as the Commander-in-Chief of the Continental Army against the British, didn't declare himself as the president of the USA on the day the declaration was adopted. Instead, he continued to fight till 1783 when the Treaty of Paris was signed and the sovereignty of the United States of America was recognized. He took office as president on April 30, 1789.having been duly elected in 1788.
The minority government of Ian Smith of Rhodesia, now Zimbabwe also adopted a unilateral declaration of independence on November 11, 1965 in order to deprive its majority African citizens of their due share in the government. The declaration was, therefore, deemed as illegal by the British, the Commonwealth and the United Nations. No country recognized Rhodesia. A guerrilla war between the illegal government and two rival African nationalist groups began. The war continued until Rhodesia revoked its UDI and the UK granted independence to Zimbabwe in 1980. There are similar examples of unrecognized UDIs like those of Ireland in 1919, Biafra in 1967, Northern Cyprus in 1983 and Crimea in 2014.
All recognized recent UDIs were made either by an act of parliament or by individuals who were elected representatives of the people and/or recognized legendary leaders like Ho Chi Minh of Vietnam (1945), Sukarno and Mohammad Hatta of Indonesia (1945), Tunku Abdur Rahman of Malaysia (1957) and Bangabandhu Sheikh Mujibur Rahman of Bangladesh (1971). An UDI by an individual carries no significance unless it is endorsed by a duly elected parliament. All UDIs must also be recognized by a vast majority of countries and the United Nations.
In recent history, there is no example of a country becoming independent through a UDI made by a hitherto unknown individual. Moreover, none becomes the president of a country simply by announcing a UDI on radio or television. Any such claim by anyone is simply a travesty in historical perspective.

The writer is a former chief engineer of Bangladesh Atomic Energy Commission.