Starting from 265 BC, Qin launched a massive invasion on Han and forced Han to cede its territory of Shangdang (上黨; in present-day Shanxi province). However, Han offered Shangdang to Zhao instead, which led to a conflict between Qin and Zhao for control of Shangdang. Qin and Zhao engaged in the three-year-long Battle of Changping, followed by another three-year siege by Qin on Zhao's capital city of Handan. The conflict at Changping was deemed as a power struggle, as both sides pitted their forces against each other not only on the battlefield, but also in the domestic context. Although Qin had an abundance of resources and vast manpower, it had to enlist every man above the age of 15 for war-related duties, ranging from front-line service to logistics and agriculture. King Zhaoxiang of Qin even personally directed his army's supply lines. The extent of mobilization and the exhaustion in the aftermath was not seen in world history for another 2,000 years, until this concept of total war re-entered the stage during World War I. Qin's eventual victory in 260 BC was attributed to its use of schemes to stir up internal conflict in Zhao, which led to the replacement of Zhao's military leaders.