Complex sentence: Frustrated with the violence associated with the IPHL, he left the league late in 1906 and returned to Canada, where in 1907 he helped the Montreal Wanderers win the Stanley Cup, the national championship trophy for hockey.
Split into simpler sentences: Frustrated with the violence associated with the IPHL, he left the league late in 1906 and returned to Canada. In 1907 Stuart helped the Montreal Wanderers win the Stanley Cup, the national championship trophy for hockey.