Zeev Wolf (William) Scharf responded to the call of the Zionist leadership - David Ben Gurion, Yitzhak Ben Zvi and Pinchas Ruttenberg, who were then in the US - to join the Jewish Brigade, which was established within the British Army, under the command of Captain Joseph Trumpeldor to help liberate Eretz Yisrael from the Turks. Very little is known of Zeev Scharf's background before arriving in Palestine. He is believed to have been born in Poland and traveled to Canada and then the United States. On August 9, 1918, Scharff enlisted in the 39th Battalion, according to British records. As he enlisted in August 1918, Scharff would likely have reached Palestine in time to perform some peacekeeping activities before demobilization. He was released from the military on February 16, 1920, and less than two weeks later, he made his way to Tel Hai.
On March 1, 1920, he and seven others (including Trumpeldor) died defending Tel Hai against an Arab attack and were buried in a common grave on the hill between Tel Hai and Kfar Giladi.
On the ruins of the Arab village of Halsa, from which the attackers came, was built the city of Kiryat Shemonah, named after the eight who fell.
For more information about the fight for Tel Hai, see https://www.timesofisrael.com/the-hidden-american-history-of-one-of-zionisms-foundational-battles-tel-hai/