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:
Genghis_Khan

Context:
For the next several years, Hoelun and her children lived in poverty, surviving primarily on wild fruits and ox carcasses, marmots, and other small game killed by Temüjin and his brothers. Begter, Temujin's older half-brother, began to exercise the power of the eldest male in the family and eventually Temujin's mother Hoelun (not Begter's mother) would have to accept him as her husband if and when he became an adult. Temujin's resentment erupted during one hunting excursion that Temüjin and his brother Khasar killed their half-brother Begter.

Question:
Who killed Begter, Temüjin's half-brother?

Temüjin and his brother Khasar