GUERNSEY, Channel Islands (AP) _ It vexed the likes of Jane Austen. And now, primogeniture _ the feudal practice that means only eldest sons can inherit property _ is troubling two multimillionaires in the Channel Islands.

The 61-year-old twins David and Frederick Barclay want to leave their island, Brecqhou, and their huge castle to their four children, including a daughter.

On Friday, a legal battle began between ancient customs of the islands, which have been possessions of the English Crown since 1066, and such modern notions as sexual equality and human rights.

The Barclays went to court to try to prove their 160-acre island falls under the jurisdiction of Guernsey island, with its more modern laws, instead of Sark, where the law of primogeniture still holds sway.

Guernsey is 6 miles from Brecqhou, which is separated from tiny Sark by a mere 100 yards of choppy water.

Queen Elizabeth II is joining the seigneur of Sark, its feudal ruler, in resisting the Barclays.

After five hours of legal arguments behind closed doors on Friday, the case was adjourned to next week _ and could last months, even years.

Things have never changed easily in these islands, which lie in the English Channel about 35 miles off the coast of France.

They became possessions of the English Crown when the Normans conquered England in the 11th century and have never been part of the United Kingdom. They remain Crown dependencies, have their own separate laws, and are not bound by acts of the British Parliament.

Sark, with a population of 570, has its own parliament, no income taxes and a ban on cars. The members of the tiny legislature _ called the Chief of Pleas _ are the owners of the 40 properties on Sark.

It's been that way since 1565, when Elizabeth I granted a nobleman, Hellier de Carteret, the fiefdom of Sark _ which includes the island of Brecqhou.

As part of the deal, the ruler of Sark would provide 40 armed men _ the 40 property owners _ who swore allegiance to the monarch. Primogenture keeps the properties from being broken up and dispersed among many children. If the owner has no son, his property goes to the eldest daughter, and about one-third of the current owners on Sark are women.

Primogeniture long ago ceased to apply to the average Briton. Among many landed aristocratic families, however, estates are still passed on from father to eldest son, a practice that has kept estates intact over the centuries.

The problems created by primogeniture drove the plot of several Austen novels in the 18th century, ``Pride and Prejudice'' in particular. How does a family of all daughters find good husbands for girls with who cannot inherit their family's property, and thus have no dowries?

The reclusive Barclay twins, owners of London's Ritz Hotel, spent about $42 million dollars to build their huge Gothic-style castle, whose towering granite walls enclose homes for individual family members, a library, a games room, two indoor swimming pools, a chapel and a weatherproof atrium.

The legal battle prompted David Barclay to give a rare newspaper interview.

Primogeniture, he told London's Daily Mail, violates equal rights.

``It is also against our basic democratic and human rights,'' he said. ``Nowhere in the Western world would this be tolerated. Anyone must have a right to do what they wish with their assets.''

The seigneur of Sark, Michael Beaumont, a 68-year-old former aeronautical design engineer who inherited the title from his grandmother, the Dame of Sark, in 1974, is resisting them.

He expressed surprise at the Barclays' behavior.

``They just seemed like quiet businessmen really, soberly suited and showing no signs of flamboyance,'' he said. ``I had several nice letters from them _ now this.''