A mace is basically nothing more than a wooden club with a head made of some heavy and hard material, such as stone. Stone mace heads were first used nearly 6,000 years ago in predynastic Egypt. The earliest known are disc maces with odd but beautifully formed stones mounted perpendicularly to their handle. As one of the earliest weapons in ancient Egypt, the mace was guaranteed fame as a source of Pharaoh's prowess for some 3,000 years, long after it was abandoned as a practical weapon. 

In fact, even as early as the Protodynastic Period, we find the surface of the mace head, like the ceremonial cosmetic palettes of Egypt, adopted as a vehicle for royal propaganda. Hence,  very early on, depictions of the Scorpion King are found on a limestone mace head, as well as portrayals of Narmer on another, both dug up at the so-called Main Deposit of the temple at Hierakonpolis (both now in the Ashmolean Museum at Oxford). We also see Narmer wielding the mace in order to smite his enemies depicted on his Palette (Egyptian Antiquities Museum), and almost three thousand years later, even Egypt's Roman pharaohs continue to smite their opponents with the same weapon, at least on temple walls. Perhaps this is due to the fact that the mace is a weapon requiring great force, rather than dexterity, and so they became symbols of great power. However, we must also see that the Egyptians had great respect and a fascinated interest in their own antiquity, and the mace head was, after all, one of the very earliest symbols of Egypt's ancient power. 

Maces as a weapon were used extensively in Egypt and neighboring Canaan, as well as other areas of the world. However, in regions where armor and helmets were worn during combat, such as Mesopotamia, their use was limited. 

The problem with early maces is that their stone heads shatter fairly easily and it was difficult to fix the head to the wooden handle reliably. Really, few improvements were ever made to maces. The Egyptians attempted to give them a disk shape in the predynastic period (Naqada I  about 3850-3650 BC) in order to increase their impact and even provide some cutting capabilities, but this seems to have been a short lived improvement. In fact, there is a possibility that such mace heads were made to mimic a lotus plant. 

A rounded pear form of mace head  known as a "piriform" replaced the disc mace in the Naqada II period of pre-dynastic Upper Egypt (3600-3250 BC) and was used throughout the Naqada III period (3250-3100 BC). Similar mace heads were also used in Mesopotamia around 2450-1900 BC. 

An important, later development in mace heads was the use of metal for their composition. With the advent of copper mace heads, they no longer shattered and a better fit could be made to the wooden club by giving the eye of the mace head the shape of a cone and using a tapered handle. 

Yet time and again, we continue to find at least the pharaoh smiting his enemies with the mace. More than 1,500 years after the Scorpion King was depicted upon a mace head, we find inscribed on a Stela of Amadeh the 18th Dynasty King, Amenhotep II, recording that:

"His Majesty returned in joy of heart to his father Amun; his hand had struck down seven chiefs with his mace himself, which were in the territory of Takhsi"

Seti 1 Smiting the enemies of Egypt

During the Middle Ages, the mace did make a final appearance as the armor piercing "morning star". This weapon employs a star spiked mace head connected to a chain in order to increase its speed and thus its penetrating power. 

The Roman Ruler, Trajan, smiting his enemies with a mace head

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