As a young woman in the 1960s, Sian Elias was determined not to be ordinary or, as one friend recalls her saying, not to be "an Austin 1100, suburban housewife".

And she got her wish. She has had an eventful legal career, capped by her appointment as New Zealand's first woman Chief Justice.

And naturally she has the services of a Crown limousine. But Sian Elias is no judicial show-pony.

Beyond her graciousness and charm, she has been the lightning rod for trouble in the past two years between the Government and the judiciary.

There have been occasional mutterings in the Beehive about why she doesn't stand for Parliament if she wants to get political.

And occasional nervousness. As Chief Justice, Elias becomes "administrator" in the Governor-General's absence, acting proxy head of state with the ultimate power to dissolve Parliament.

The nervousness is over the possibility that some day she might actually do it, although she probably never would.

Less facetious is a subtle change in attitude by the Government to legislation as a result of a more suspicious relationship between the judiciary and the Executive.

At the peak of disgruntlement about Elias last year, senior Government members were heard to talk of the need to "Sian-proof" legislation.

That means leaving as few ambiguities and loose ends in legislation before Parliament as possible in order to leave no room for later judicial activism, the usually pejorative term to describe development of new principles of law by judges to justify their decisions.

Or as those deemed "activists" see it, the term given to judges by people who don't like their decisions.

The relationship appears to be in a cautious phase at present, with the players determined to give no cause for complaint after ill-judged outbursts by both Elias and State Services Minister Trevor Mallard last year.

If the relationship was perceived as hostile, it's not a description that can be pinned to Elias in any personal sense. Quite the contrary.

If there were one trait no one who knows her would argue with, it is that she is gracious in all things, even under fire.

Act MP Stephen Franks knows from experience. He was pilloried for suggesting in Parliament that Elias left open an appearance of bias by sitting on the foreshore and seabed case because of a case she had argued before the Waitangi Tribunal over control of the Manukau Harbour and seabed.

A short time later he was at a function on the legal cocktail circuit at which two High Court judges abused him, one calling him a disgrace to his profession for his criticism.

Elias was at the same function and made a beeline for him, not to castigate him but to engage him in discussion about what he had said.

Elias did not figure largely on the radar of this Government until two years into its first term, when it discovered she had disciplined a senior Auckland judge 18 months earlier for accessing soft porn on his High Court computer. The fact that she had not told the Attorney-General of this was as great a sin in the Government's eyes as the judge's actions and seen as protecting "the boys' club".

For its part, the judiciary and many in the legal profession were disturbed at the public flogging by the Government and the none too subtle pressure to get Justice Robert Fisher to resign.

Elias' leadership was undoubtedly appreciated then by her brethren on the Bench, but that was likely shaken last year when she raised the possibility that judges could be swayed by financial considerations.

It was an argument in favour of a better remuneration package and in the worthy promotion of judicial independence, but it failed spectacularly to enhance the standing of judges.

The recent tension between the Executive and the judiciary has centred around two things: opposing views on the notion of "the sovereignty of Parliament", and the way Elias has gone about criticising the Government for what she perceives is ignorance over the importance of judicial independence - bleating about it to overseas audiences and declaring the Prime Minister to have "a profound lack of understanding" of judicial independence.

But the undercurrent has been the Government's horror at the Court of Appeal's foreshore and seabed judgment, led by Elias.

It could be said that the landmark case was one she had been in training for throughout her legal career.

The decision of June 2003 allowed for the possibility that the Maori Land Court could issue freehold title over the foreshore and seabed.

Addressing the consequent legal uncertainties and upheavals in Maoridom dominated the political agenda for the next 18 months.

Elias is a heroic figure among those whose passion is Maori justice, and a key figure in what is so disparagingly termed the treaty industry. She has a reputation for compassion and humanity.

So did her father, the son of Armenian refugees, who practised as a GP for many years in West Auckland.

Elias arrived in New Zealand with her father and Welsh mother as a toddler from London. She was raised in Titirangi and went to the private Anglican school Diocesan School for Girls in Epsom.

Skipping the upper sixth form after getting University Entrance, she started at Auckland University's law school in 1966, one of only half a dozen girls, including former Attorney-General Margaret Wilson, in a class of well over 100 boys.

But while the young Wilson was resolute in all things and a political creature, it was not clear at the time that the cultured young Westie would earn a name synonymous for championing legal justice issues for Maori.

That evolved through her career, rather than existing as a driving force from the outset.

At university she was part of the Dio set, stylish, fun without being flamboyant.

She studied hard but was not among the scholarly elite of her cohort. She was part of a generation that wanted to change the world but she was a strong advocate of the legitimacy of change from within the system.

She preferred to observe demonstrations from the independence of the footpath, where good law students should be, rather than join the melee.

Elias joined the Auckland aristocracy and the Fletcher dynasty when she married Hugh Fletcher in 1970. The pair studied further at Stanford University in California, where she gained a masters in law.

The couple have two grown sons.

Elias has been one of New Zealand's most notable models of affirmative action for women.

She and close friend Lowell Goddard were chosen to become the first women Queen's Counsel in 1988, and in 1995 Elias was appointed a High Court judge.

She has New Zealand's first woman Prime Minister, Jenny Shipley, to thank for her job as the country's first woman Chief Justice - a position commonly appointed not only from the other gender but from outside the judiciary.

Elias' appointment may have been a surprise to the legal profession, but it was no surprise to the Cabinet colleagues of Shipley, who made no secret of the fact that she was determined to appoint a woman.

Elias beat present Court of Appeal Judge John McGrath, then Solicitor- General, to the job.

She is a successful model of affirmative action. No one in the legal profession the Herald spoke to disputes that she is up to the job of Chief Justice, even her critics.

One of her most notable judgments as a High Court judge directly affected politicians in the David Lange vs Joe Atkinson defamation case.

The final outcome on appeal was to give the news media a stronger defence against defamation actions by politicians.

As a lawyer, she specialised in company law and was leading counsel for the plaintiff in the long-running Equiticorp case.

But it is her association with Treaty of Waitangi law for which she attracted headlines.

With two small boys in 1979, Elias was working part-time at the Grey Lynn neighbourhood law office when she worked for some Maori and Pacific Island defendants accused of attacking a haka party of Auckland University engineering students.

In 1984, she helped Nganeko Minhinnick's Manukau Harbour claim to the Waitangi Tribunal, a case that opened up a new world to her.

It also led to work on other treaty cases, including a claim to prevent the Government selling radio frequencies, and the case challenging the 1994 Maori electoral option.

The work has given her an appreciation of Maori custom and aspirations that she fosters today among the judiciary and in her private life.

Every Waitangi Day she makes a pilgrimage as a private citizen to Waitangi, something Shipley does as well.

When she was appointed Chief Justice, Elias told the Herald: "One of the reasons I'm so optimistic about the future is because what happened at Waitangi [the signing in 1840] is so consciously founded on an expectation that justice will be achieved through law."

Her first words last year at the first sitting of the new indigenous Supreme Court were to acknowledge the presence in the public gallery of an unassuming Maori couple, invited for the occasion to represent the tangata whenua, Te Atiawa.

Elias was made Chief Justice at the young age of 50. The compulsory retirement age of 68 means that over 18 years she has the potential to leave an imprint on the law in New Zealand. But it is unlikely she will stay that long.

Five years into the job, she is half- way through her term as New Zealand's top judge, saying when she was appointed that she saw it as a 10-year position.

But she may have changed her mind given the way her job has changed. The position of Chief Justice carries more weight and is more powerful today than it was five years ago. Elias now assumes the mantle of pre-eminent jurist as head of the Supreme Court.

Before the Supreme Court was established last year, the Chief Justice was more of an administrative role, with the right to sit on any case.

The president of the Court of Appeal was regarded as the pre-eminent jurist, and no more so than under the tenure of Sir Robin Cooke, later Lord Cooke of Thorndon.

He made a deep imprint on not just the law but on the continuing debate over the sovereignty of Parliament and, undoubtedly, on the development of Elias' career.

One of his earliest challenges to the sovereignty of Parliament still cited by his acolytes was contained in a 1984 judgment involving, of all things, the Poultry Board, when he said "some common law rights presumably lie so deep that even Parliament could not override them", which is tantamount to saying that in extreme circumstance, the courts can overrule the will of Parliament.

It is a good guess that Elias is one of his admirers - she did not consent to an interview - and if she wasn't in Cooke's early days, she certainly would have been after 1987.

That was when he handed down his Court of Appeal ruling in the case of the Maori Council vs the Attorney-General, establishing a key principle of the Treaty of Waitangi as "partnership".

It was a stunning judgment and a victory for the Maori Council and its team of lawyers - David Baragwanath, now a High Court judge, the late Martin Dawson and one Sian Elias.

Its significance, however, was adjudged through the passage of time with its "partnership" principle being fostered by successive Governments in many areas of state.

The suspicion with which the judiciary and Elias is regarded in some parliamentary quarters is not over a simple academic argument about the sovereignty of Parliament but because of a belief that those who would dismiss it are often activist and more likely to deliver decisions of the foreshore ilk - with a devil-may-care attitude to its consequences.

Cooke is still going strong. In his most recent speech, he described the sovereignty of Parliament as a "catchphrase beloved by some sections of the media and some politicians" which "does not survive in-depth analysis".

Elias has picked up Cooke's baton.

She began her run in a speech in Melbourne in 2003 about parliamentary sovereignty, describing it as a merry-go-round.

"We have assumed the application of the doctrine of parliamentary sovereignty in New Zealand. Why is not clear," she said.

"Parliamentary sovereignty is an inadequate theory of our constitutions. An untrammelled freedom of Parliament does not exist ... We should get off the merry-go-round."

The words of a woman who has found a confidence in her role as Chief Justice - and no doubt of a woman determined not to be an ordinary Chief Justice.

The Chief Justice

* Heads the judiciary.

* Presides over the Supreme Court.

* Stands in for the Governor-General if necessary.

* Manages the relationship between courts and other branches of Government.

* Advises the Attorney-General on judicial appointments.