You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Samurai

Context:
After the Genpei war of the late 12th century, a clan leader Minamoto no Yoritomo obtained the right to appoint shugo and jito, and was allowed to organize soldiers and police, and to collect a certain amount of tax. Initially, their responsibility was restricted to arresting rebels and collecting needed army provisions, and they were forbidden from interfering with Kokushi Governors, but their responsibility gradually expanded and thus the samurai-class appeared as the political ruling power in Japan. Minamoto no Yoritomo opened the Kamakura Bakufu Shogunate in 1192.

Question:
What was Minamoto's position?

clan leader