The British origins of common law
The common-law system first developed in England and is therefore often referred to as ‘English common law’. Upon colonisation by the British, Australia adopted a common-law legal system. Other countries using this system include Great Britain, Canada, New Zealand and the United States of America.
Common law can be best described as a collection of legal principles and rules that is derived from the decisions of judges in higher courts. However, the term ‘common law’ – or ‘judge-made law’ – is also used to differentiate between law that is developed by judges and law that is imposed by parliaments. It is this second usage that is most commonly associated with common law.
Judges are required to obey statute law; that is, law developed by parliament. However, when no relevant statute law exists a judge will turn to common-law principles to resolve the dispute. A judge may also use common law in order to interpret statute law. If both common and statute law exists, then the statute law must always be followed

HISTORICAL DEVELOPMENT OF COMMON LAW
Common law developed after the Norman invasion of England in the 11th century. In order to consolidate his position in the newly conquered country, William the Conqueror sent judges around the country. They were given three main tasks by the king:
1 to administer a uniform set of laws throughout the country
2 to report to the king any threats to the throne
3 to assess the wealth of the country in order to determine what taxes could be levied.
By the end of the 12th century the practice of sending royal justices throughout the country ‘on circuits’ was well established. These royal justices ensured that their rulings were similar, thus developing the conceptof precedent. As a consequence, a set of quite uniform laws developed throughout the country. In 1258 the Provisions of Oxford – a form of constitutional control on the king – were drawn up. One effect of this was to greatly reduce the flexibility of common law. In essence, it required a case to fit into a precedent that had already been set, which made it very difficult for a person to bring a case that was new.

INJUNCTION A court order that requires a person not to do something; for example, not to print a particular story in a newspaper.
SPECIFIC PERFORMANCE A court order that requires
a person to fulfill an obligation they undertook as part of
a contract.

Equity
The inflexibility introduced into the common law by the Provisions of Oxford led many people to turn to the King to have their disputes heard. They believed that justice could only be achieved through the King, who was the ‘guardian’ of justice and had discretionary power to overrule any decision made by the courts. This became an effective way for people to bring cases for which there was no precedent. The King decided on cases using the concept of equity (or fairness) and his conscience. In essence, the King’s decision was based not on the dictates of precedent but instead on achieving the fairest outcome.
The Office of the Chancellor had grown in power and prestige during the reign of Henry II (1154–1189). The Chancellor played many roles: he was the King’s secretary, the royal Chaplain and – importantly – the ‘keeper of the King’s conscience’. The King was thus able to delegate to the Chancellor the role of hearing and deciding on the growing number of disputes that came to the King for resolution.By the 14th century, the Courts of Chancery had been established to administer a new set of laws: the laws of equity. These courts provided a far wider range of legal remedies than the common-law courts; for example, the main remedy in common law is to order monetary compensation, while, equity law provides for other remedies, such as injunctions and specific performances, which are more in keeping with the concept of fairness. Over time, two types of judge-made law developed: common law and equity.

The main principles of equity law