Militarily in addition to expanding his existing naval forces, Zheng created land forces. However, because official resources were lacking, Zheng's army were closer to being household retainers rather than of being true professional soldiers; their role being to protect the group's trade by providing security both at sea and ashore. Income from the group's trade activities went back into the maintenance of its military, the relationship with the government being similar to modern outsourced private military contracts rather than being part of the official Ming military.