Engineering dates back to the Dark Ages when people started building walls around things to keep other people out. A group known as the Scientists produced massive, expensive structures with a tendency to crash down on themselves, and often infested with bugs, to surround Castles, Towns, China, etc.

Often wars would collapse into one party surrounding another party's Castle, Town, subcontinet, etc. and shouting insults. This got to be rather boring.

Scientists were first hired to solve this problem. They came up with the concept of the "Anti-Wall." The idea was to build larger and larger walls around the first wall. The enemy would be jealous of the new walls, and come out of theirs to take yours, and you could slug them then. After blowing out the King's budget to no avail, scientists where all impaled on large stakes with lots of nasty barbs and things.¹

The Kings and Emperors, strapped for cash, decided to hire the kid down the street who was constantly taking his parents walls apart, and not-so-successfully put them back together.

The idea was to get enough of these wall disectors to disassemble the the enemy's walls. Once down they would lunge in with their armies to rape, pillage, and burn. ²

However while clever, these wall disectors were very lazy. Since taking the entire wall apart was too much work, they decided forgo that part, and focus on ways of getting armies over, through and beyond the walls.

Their inventions, the product of an ingenious mind, are engines. Since these engines were used to break up seiges, so the ladders, towers, battering rams, catapults and junk mailing lists came to be known as "Siege Engines." In the english language it is traditional to create a title for someone by tacking on an "er" sound to what they do. ³

Hence, we get the title Engineer.