Gaddafi became head of state of Libya after removing King Idris from power in a 1969 bloodless coup. He ruled Libya from September 1, 1969 to August 23, 2011. After the coup, Gaddafi established the Libyan Arab Republic. He was one of the longest-serving non royal rulers in history, because he had ruled for more than 41 years. Gaddafi used Arab socialist and Arab nationalist ideas. He published a book about his philosophical views in 1975. This book is commonly known as "The Green Book". In 1977, he left the power of Libya, and continued playing role of revolutionary. People called him the "Brother Leader and Guide of the Revolution".