Archaeology: Piecing together the jigsaw: Israel's mosaics are of great significance to Jews and Christians, says David Keys

ONE OF the greatest collections of Roman mosaic works of art ever found is being unearthed in northern Israel, inside a now long-deserted city that played a key role in the development of Jewish religious teaching. Around 1,000 square metres of mosaics have so far been excavated, including the largest mosaic pavement ever discovered inside a synagogue.

The ancient city now being excavated - Sepphoris, once the capital of Galilee - is of considerable significance to both Jews and Christians. In pre-Roman times, Sepphoris was already home to many religious scholars who became high priests of the temple in Jerusalem. Sepphoris was also only three miles away from Nazareth.

During the Jewish revolt against Rome in 66-70AD, Sepphoris officially declared itself a 'City of Peace' and - possibly under the influence of upper class priests - refused to join the rebellion.

In the 2nd century, it also appears to have been home to a group of Minim (Judeo-Christians), who were only later absorbed into mainstream early Christianity. But it was in the early 3rd century AD that the city became most important in Jewish history, becoming for a period both the official administrative centre and the intellectual heart of the Jewish faith.

Between 200 and 217AD, the top Jewish religious body - the Sanhedrin - was based there, and it was during this same period at Sepphoris that the core material of the Jewish religious book, the Talmud, was first collated and edited.

Israeli archaeologists, led by Professor Ehud Netzer and Zeev Weiss of Jerusalem's Hebrew University, are now unearthing the remains not only of houses and religious structures (mainly ritual baths) from this early Talmudic period, but also spectacular evidence that the city continued to be a major Jewish centre until at least the late 6th century AD.

Excavations are now beginning to reveal the spectacular remains of a 5th- or 6th-century synagogue, complete with the largest synagogue mosaic ever found. Measuring 17m by 7m, it uses religious and astrological images to portray the months of the year, the four seasons, and several Jewish festivals. The mosaic's central panel consists of a giant zodiac complete with the names of the months and astrological signs written in Hebrew.

Around the borders of the zodiac, the four seasons are represented by young women, wearing clothing appropriate to each particular time of the year. The new year itself is symbolised by a ram's horn of the type still used in Jewish New Year services today.

The harvest thanksgiving festival, Sukkoth, is symbolised by images of limes, palm fronds, myrtle leaves and willow branches, while the festival commemorating the giving of the Ten Commandments - Shabuoth - is represented by what had originally been a temple offering of a basket of fruit.

The giant mosaic also portrays the Ark of the Law, a menorah - the seven-branched Jewish candelabra - and an enigmatic pair of lions holding the head of a bull.

Although the synagogue mosaic is the largest so far found at Sepphoris, it is by no means the only spectacular example of the art in the city. Archaeologists have so far uncovered a grand total of 30 major mosaics.

In the ruins of one palatial 3rd- century mansion, excavations have revealed what some art specialists have described as the Roman world's Mona Lisa. It is an extraordinarily beautiful mosaic depiction of a young woman wearing earrings and a garland of laurel leaves. The same mosaic pavement portrays a series of lively scenes, including a drinking contest between two gods, and a Nile river scene with naked hunters in hot pursuit of a crocodile.

Another mosaic, this time inside what seems to have been a great public building, boasts an extremely rare portrayal of one of the seven wonders of the ancient world - the Pharos lighthouse in Alexandria. It also shows Alexandria's city gate, as well as a figure of a semi-naked woman personifying Egypt and a figure of a man symbolising the river Nile. They both form part of a mosaic celebrating a great Nile festival. In the same building are depictions of two horse-riding Amazons hunting a panther.

The Jewish and pagan iconography of its mosaics are testimony to a remarkably tolerant co-existence - even a fruitful symbiosis - between Jewish and Roman cultures.

When the core of the Talmud was being collated in Sepphoris in the early 3rd century AD, the Jewish authorities even went so far as to mint coins proclaiming a 'covenant of friendship and mutual aid between the (Jewish) Holy Council (the city government) and the Senate of the Roman People.'

It was this time of this Roman/Jewish co-operation that the Talmud was born, and the codifier of its core material (the Mishnah), the great rabbi Yehuda Hanasi carried out his redaction work in Sepphoris.

Known as Judah the Prince, he seems to have been a personal friend of the Roman emperor, Caracalla, who described Sepphoris as 'the Holy City', although whether for pagan or for Jewish reasons - or both - is ambiguous.

Investigations at the site of Sepphoris will continue for several years, and dozens more magnificent mosaics are likely to be discovered.

The excavations and some of the mosaics at Sepphoris (near Zippori, 16 miles east of Haifa) are available for public viewing daily, 9am to 5pm.