Civil engineering is a professional engineering discipline that deals with the design, construction and maintenance of the physical and naturally constructed environment, which includes works such as roads, bridges, canals, dams and buildings. Civil engineering is traditionally divided into several subdisciplines. It is the second oldest engineering discipline after military engineering and is defined to distinguish non-military engineering from military engineering. Civil engineering is carried out in the public sector from the municipal government to the national government, and in the private sector from individual owners to international companies.
Engineering has been an aspect of life since the beginning of human existence. The oldest practice of civil engineering may have begun between 4000 and 2000 BC in ancient Egypt, the Indus Valley civilization and Mesopotamia (ancient Iraq) when humans began to abandon a nomadic existence, creating the need to build a refuge . During this time, transportation became increasingly important and led to the development of wheel and navigation.
Until modern times there was no clear distinction between civil engineering and architecture, and the term engineer and architect were mainly geographical variations that refer to the same occupation, and which are often used interchangeably. The construction of pyramids in Egypt (circa 2700-2500 BC) were some of the first instances of building large structures. Other ancient civil engineering constructions include the Qanat water management system (the oldest is more than 3000 years old and more than 71 km), the Parthenon of Iktinos in ancient Greece (447-438 BC), the Appian Way of the Roman engineers (c. 312 BC), the Great Wall of China by General Meng T'ien under the orders of Emperor Ch'in Shih Huang Ti (c.220 BC) and the stupas built in ancient Sri Lanka as the Jetavanaramaya and the extensive irrigation works in Anuradhapura. The Romans developed civil structures throughout their empire, including especially aqueducts, insulae, ports, bridges, dams and roads.