Under the Ming, military service became hereditary. A soldier and his family would be registered as a military household. Each of these military household’s had an obligation to produce a young man to serve in the army. The hereditary system in it’s early years had guard units numbering 5,000 men, further divided into battalions of 1,000 and companies of 100. Later, the number of soldiers in a guard unit was increased to 5,600 men, comprising of five battalions of 1,120 men, with each battalion divided into companies of 112 men. In total, the Ming army in the late 14th century numbered approximately 1.2 million hereditary soldiers. During the reign of Yongle (Zhu Di) three training camps were established, which troops were sent to in rotation. The first specialised in infantry warfare, the second in cavalry warfare and the third in artillery. While this worked very well at first, it stagnated after 1435 and had to be revived in 1464 by the Chenghua emperor.