Who is the supreme leader of North Korea? And what history lead to his rule?
The current supreme leader of North Korea is Kim Jong-un. He has been in power since December 2011, following the death of his father, Kim Jong-il, who was the previous leader of North Korea.

Kim Jong-un is the third generation of the Kim family to rule North Korea. His grandfather, Kim Il-sung, was the founding leader of North Korea and ruled the country from its inception in 1948 until his death in 1994. Kim Il-sung's son, Kim Jong-il, then took over as leader and ruled until his death in 2011.

Kim Jong-un was designated as the successor to Kim Jong-il several years before his father's death, and after his father's death, he was quickly appointed as the supreme leader. Kim Jong-un has continued his family's legacy of authoritarian rule, maintaining tight control over the country's political and economic systems and continuing to pursue a nuclear weapons program.

The history of North Korea's ruling family dates back to the country's formation after World War II, when Kim Il-sung established a socialist state in the northern part of the Korean peninsula. The Kim family's rule has been marked by a cult of personality around the leaders, strict control over the media and public expression, and a focus on military development and self-reliance.
Has there ever been an attempt to overthrow the North Korean government?
There have been various attempts to overthrow the North Korean government over the years, but none have been successful. The North Korean government has a highly centralized and tightly controlled system that makes it difficult for opposition groups to gain any significant traction.

One of the most well-known attempts was the 1968 capture of the U.S. Navy intelligence ship USS Pueblo by North Korean forces. The incident led to a failed attempt by the U.S. to rescue the crew, and the crew was eventually released after 11 months of captivity.

In addition, there have been various guerrilla groups and underground organizations that have sought to overthrow the government, but their efforts have been largely unsuccessful.

The North Korean government maintains tight control over information and limits the freedom of its citizens, making it difficult for opposition groups to gain momentum. The government also maintains a large and well-equipped military, making it difficult for any external forces to attempt to overthrow the government by force.