When Susan Kiefel left school at the age of 15 in 1969, as did many young women in that era, she no doubt never imagined that one day she would be appointed as chief justice of Australia.

That day will come in January next year. Kiefel’s rise to the top of the judicial system is a story of fierce determination and an extraordinary work ethic. Noel Pearson, in a different context, often speaks of the soft bigotry of low expectations. Kiefel obviously had no such low expectations of herself, even if others in that era dismissed young women in this way.

While working as a legal secretary, she matriculated and then, instead of undertaking a university law degree, studied in the evening to qualify in law through the Barristers’ Board. One is left wondering how many other legal secretaries could have been chief justice but were denied the opportunities to set them on that path.

At 21, when most law students are struggling to finish their university degrees, Kiefel was called to the Queensland Bar, leaping ahead of her contemporaries who had taken the more orthodox path.

She already had practical legal experience under her belt, having worked full time as a legal clerk in a law firm from 1973. Kiefel took to the Bar with relish, taking silk 12 years later in 1987. In the meantime, in 1984, she took a break from the Bar, undertaking a master of law at Cambridge, winning a prize in comparative law.

Kiefel’s study of how the law works in other places and in particular the jurisprudence of the European Court of Justice, during a later fellowship at Cambridge, influenced the development of her own jurisprudence.

In 1993, Kiefel accepted an appointment to the Supreme Court of Queensland and moved across to the Federal Court the following year. She was appointed to the High Court by the Howard government in 2007. Her elevation to the office of chief justice will be the latest step in a remarkable journey.

During her time on the High Court, Kiefel has been most notable for her advocacy of a European style test of proportionality, a test judges use to assess whether a law is really enacted for a legitimate purpose or as a means of avoiding limitations in the Constitution. Kiefel has argued for a structured test that assesses whether the law is proportional to its purpose. Her argument is that the court must try to avoid value judgments and that its reasoning must be clearly exposed.

She has gradually persuaded fellow judges to join her approach, culminating in majority support for it in the McCloy case last year, in which the court upheld caps on political donations in NSW and bans on donations by property developers. That majority, however, has proved fragile and appeared to fracture in the more recent Murphy case (2016) in which the High Court rejected a challenge to the closing of the electoral rolls before a federal election.

It remains to be seen whether Kiefel, as chief justice, can claw back and consolidate majority support for this approach.

One interesting difference between Kiefel and her predecessor as chief justice, Robert French, is their approach to the commonwealth’s executive power, particularly in relation to the contro­versial decision in 2001’s Tampa case concerning the ability of the commonwealth to exclude and detain asylum-seekers without the support of legislation.

When French was a justice of the Federal Court, he held that the commonwealth government had an executive power to detain the asylum-seekers on the Tampa for the purpose of excluding them from entering into Australia. He concluded that this executive power was not extinguished by the enactment of legislation concerning migration matters.

Some argue it was this decision that brought French to prominence, ultimately resulting in his appointment as chief justice of the High Court.

French continued to support his broad view of commonwealth executive power in the CPCF case last year concerning the detention of Sri Lankan asylum-seekers who were trying to reach Christmas Island.

But Kiefel considered that any executive power to detain asylum-seekers had ceased to exist and that the commonwealth must legislate if it is to detain people for the purposes of excluding or deporting them.

A majority of the court held that the government’s actions were supported by legislation, so it did not matter whether or not it was also supported by executive power. It is notable, however, that despite her narrower views on the scope of the commonwealth government’s executive powers, Kiefel was still appointed to the office of chief justice.

Apart from its symbolic status in the court hierarchy in Australia, the role and significance of the chief justice is relatively fluid. In a recent speech French said that he had never claimed to be “first among equals” as chief justice but rather “one among equals”.

Nonetheless, some chief jus­tices, such as Owen Dixon, have held a strong influence over their fellow judges through the sheer force of their intellect.

For this reason the court is often described by reference to their term of office, such as the “Mason court” or the “Gleeson court”.

The Mason court, for example, under ninth chief justice Anthony Mason from 1987 to 1995, was known for its development of constitutional implications, such as the implied freedom of political communication in 1992.

Other chief justices made their mark through their administrative role in reorganising how the court operated, such as the introduction of the requirement to obtain special leave for appeals during the chief justiceship of Harry Gibbs, Mason’s predecessor.

Garfield Barwick played an important part in the construction and fitout of the High Court building on the shores of Lake Burley Griffin, sitting on the panel that judged the architectural plans and supervised its construction.

His eye for utility and perfection went as far as the construction of the book trolleys wheeled into court. Library attendants still wax lyrical about the steering capability of the bespoke book trolleys from Barwick’s era, in contrast to the off-the-shelf models today that have defects on a par with supermarket trolleys.

The chief justice is the conduit between the court and the government. That relationship sometimes can be fractious, particularly when it comes to budgetary matters and to attacks on the independence of the judiciary. In 1996, chief justice Gerard Brennan wrote to the deputy prime minister raising his concern about criticism of the court in relation to its judgment in the Wik case on native title.

This controversy was nothing, however, in comparison to the great High Court strike of 1905, when the court’s Melbourne sittings were cancelled. The cause was a dispute between chief justice Samuel Griffith and the attorney-general about shelving for the chief justice’s books.

Kiefel is likelier to find a sympathetic ear in the incumbent Attorney-General, George Brandis, when it comes to book shelving.

Nonetheless, the chief justice retains an important role in managing the court’s relationship with the government, securing its independence and the financial resources necessary for its operation.

As head of the judiciary, the chief justice fulfils several representational roles. They swear in the governor-general and act as a delegate of the governor-general in administering the oath to members of parliament. The chief justice chairs the Council of Chief Justices of Australia and New Zealand, receives diplomatic visitors and represents the Australian judiciary abroad.

The only significant legal power of the chief justice arises where the court is acting in its original jurisdiction, rather than on appeal, and the Full Court is evenly divided. In such a case the judgment of the chief justice prevails.

The administration of the High Court, however, is formally vested in the court as a whole rather than the chief justice. This was apparently the consequence of judges objecting to being ruled over by anyone, including their own chief.

Perhaps the most significant role of the chief justice is in developing collegiality on the court. How the judges discuss their views after hearings and whether they informally agree on who should write a draft judgment first depends very much on the level of cordiality among the judges, which tends to be influenced by the chief justice.

Kiefel, in listing the qualities of a model judge, which included integrity, wisdom, objectivity, a strong work ethic and courtesy, added that a most important quality was “the ability to behave in a collegiate manner”. It will be her ability to foster collegiality that will be an important mark of success in her new role.

There is a strong tendency, at the beginning of a judge’s tenure, for people to seek to label them as a “conservative” or “activist” or categorise them as forming a bloc with other judges.

Kiefel, however, has rejected such categorisation. In a speech, Kiefel agreed with a comment by Mason that he had never encountered two or more judges who share an entirely identical outlook. Kiefel acknowledged that judges might be conservative in some areas, liberal in others, and take different views in relation to the application of precedent.

Kiefel herself defies categorisation, not falling within any obvious label. Contributing to this difficulty of labelling her is the fact she often writes judgments with other judges, obscuring the distinct lines of her own reasoning. One can say, however, that she is not a “great dissenter”. Rather, she is a person who is prepared to join with others in the writing of joint judgments and the development of the law.

Kiefel’s appointment as chief justice was generally expected and will be widely welcomed by the legal profession. She was the most senior judge on the High Court and her judgments have garnered widespread respect.

Hers is a story of achievement in which many will find inspiration and encouragement.