This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

The Taira and the Minamoto clashed again in 1180, beginning the Gempei War, which ended in 1185. Samurai fought at the naval battle of Dan-no-ura, at the Shimonoseki Strait which separates Honshu and Kyushu in 1185. The victorious Minamoto no Yoritomo established the superiority of the samurai over the aristocracy. In 1190 he visited Kyoto and in 1192 became Sei'i-taishōgun, establishing the Kamakura Shogunate, or Kamakura Bakufu. Instead of ruling from Kyoto, he set up the Shogunate in Kamakura, near his base of power. "Bakufu" means "tent government", taken from the encampments the soldiers would live in, in accordance with the Bakufu's status as a military government.
When did the Gempei War begin?