Which ruler was most responsible for uniting

There are several rulers throughout history who are often credited with uniting regions or countries. However, it is difficult to determine which ruler was the most responsible for uniting, as it depends on the specific context and criteria used to measure their success.

Some notable rulers known for their efforts in unification include:

1. Genghis Khan: The founder and leader of the Mongol Empire, Genghis Khan is often credited with uniting various nomadic tribes of Mongolia and creating the largest contiguous empire in history.

2. Emperor Qin Shi Huang: The first emperor of China, Qin Shi Huang is known for his role in unifying China through the conquest of various rival states, standardization of language, currency, and the construction of the Great Wall.

3. Emperor Charlemagne: Charlemagne, also known as Charles the Great, was the King of the Franks and later the first Holy Roman Emperor. He played a crucial role in uniting much of Western Europe through his military campaigns and political alliances.

4. Otto von Bismarck: Known as the Iron Chancellor, Otto von Bismarck was a Prussian statesman who played a pivotal role in the unification of Germany in the late 19th century, bringing together multiple independent states into a unified German Empire.

5. Nelson Mandela: Although not a traditional ruler in the sense of a monarch or emperor, Nelson Mandela is often seen as the unifying figure who played a crucial role in ending apartheid and uniting South Africa, becoming the country's first black president.

Overall, it is subjective to determine the most responsible ruler for uniting. Each of these rulers contributed significantly to the unity of their respective regions, but the context, time period, and standards used for evaluation can vary.