The First Australians did not use money as we know it; they used a barter system, trading goods from one end of Australia to the other. Some popular trading items included special stones for making tools, coloured stones (ochres) used for painting, and precious pearl shells that came from the far north of Australia. 
The British sent the First Fleet to Australia to set up a penal colony. They didn’t send much money with the First Fleet because the convicts were not paid anything and the soldiers were supplied with goods for free from the Government Store, there were no stores at that time. Most of the first coins used in Australia came from the pockets of the officers, sailors and convicts who settled in Australia. These coins included English sovereigns, shillings and pence; Spanish reales; Indian rupees and Dutch guilders. It wasn’t long before there were coins in Australia from all over the world. Almost any coin (no matter which country it was from or what it was made out of) ended up being used as money in Australia.
As in 1800's the Australian population grew, a proper money system was needed. There needed to be enough money to go around, and people had to know exactly what each coin was worth. Governor King tried to solve the problem by making a proclamation, fixing the value of all of the different coins in the colony. These became known as the ‘Proclamation Coins’. However, there were still problems. There simply weren’t enough coins, and many trading ships took precious coins out of the colony as payment for cargo.
In 1813 the spanish dollar become the first circulation coin, when Governor Macquarie asked a convict named William Henshall who had been convicted of forgery to punch a round piece out of each of the Spanish dollars. 
The Spanish dollar soon fell into disuse because it was no longer worth anything. Silver coins were shipped to Australia after being made at the British Royal Mint in 1825. 
A branch of the British Royal Mint was opened in Sydney in 1855. A Melbourne branch followed in 1872 and a Perth branch opened in 1899.
In 1909, eight years after Federation, the Federal Parliament passed a bill allowing Australia to have its own coins. In 1910 the first distinctive Commonwealth coins were issued. The coins were based on the British sterling system of pounds, shillings and pence.
The government announced it was planning to convert to a decimal currency system in the coming years. Six leading artists were commissioned to submit designs for the new coins. The rules included that the design must be an Australian theme. Stuart Devlin was the artist selected and he was given six months to complete his work.
The Royal Australian Mint opened in Canberra. Australia now had its own Mint which began producing decimal coins.
The Half Penny coin was first introduced in 1911, and minting ceased in 1965 with the introduction of the decimal system. When decimalization occurred on the 14th of February, the Half Penny was not withdrawn at decimalization in 1966, and never been formally demonetized they are still a legal tender. 
George VI (Albert Frederick Arthur George 1895 – 1952) was King of the United Kingdom and the Dominions of the British 
Commonwealth from 11 December 1936 until his death in 1952. He was also the last emperor of India from 1936 until the British 
Raj was dissolved in August 1947, and the first Head  of the Commonwealth following the London Declaration of 1949.
OBVERSE: Portrait of King George VI facing left
Lettering: GEORGIVS VI D:G:BR:OMN:REX F:D:IND:IMP. HP
Translation: George VI by the Grace of God, King of all the British territories, Defender of the Faith, Emperor of India.
Engraver: Thomas Humphrey Paget
REVERSE: Kangaroo leaping to right, Country name, designers initials, date, eight pointed commonwealth star and denomination.
Lettering: AUSTRALIA KG 1943 ✸ HALF PENNY 
Engraver: George Kruger Gray
EDGE: Smooth
Designer : "HP" - Thomas Humphrey Paget (1893-1974), was British medal and coin designer and modeller.
Designer : "K·G" - George Edward Kruger Gray CBE (1880-1943), was British artist and designer
Mint : "lack of mint mark" - Melbourne mint, Australia
Mintage in 1943 33 989 000
Country                    Australia 
King                            George VI (1936-1952)
Type                             Standard circulation coin
Years                        1939-1948
Value                               Half  Penny 
Currency                  Pound (1788-1966)
Composition                 Bronze (97% Copper, 2.5% Zinc, 0.5% Tin)
Weight                         5.66 g
Diameter                   25.5 mm
Thickness                  1.7 mm
Shape                       Round
Orientation                    Medal alignment ↑↑
References                    KM# 41, Schön# 22