Team Yondaime last fought as a complete team in the war with Hidden Rock. Unfortunately Uchiha Obito lost his life in battle, though not before donating his eye to Kakashi.
got this from Groups and Teams
well when he was still in a team of three like naruto he had been on an ,ission where a bunch of rocks crushed his eye and his friend had given died saving his life but his sharingan eye was still intact so teh medical ninja in teh group put teh sharigan eye in him as a way of thanks for saving her life
