WHEN it is officially opened tomorrow, the Millennium Bridge will become the latest in a long line of structures to span York's rivers. Manufacturing problems and floods have conspired to delay the completion of the Millennium Bridge. But the finished article looks stylish and sturdy, so the calamity of 1154 should not be repeated.

All those centuries ago, the appearance of the newly-appointed Archbishop of York, William Fitz-Herbert, was enough to draw a huge crowd. The star-struck melee poured onto a wooden bridge, close to where Ouse Bridge stands today.

The structure collapsed under their weight. That can't have been the sort of omen the new Archbishop was looking for. As the men, women and children plunged into the icy waters, he could do no more than make the sign of the cross.

Mercifully, no one drowned, and a chapel was erected as a symbol of thanksgiving on the rebuilt bridge.

In the 14th and 15th centuries, Ouse Bridge was a busy commercial centre. A book of rents from the time records receipts from many from different shops.

A fresh-water fish market was held on the Staith at the foot of Ouse Bridge steps. That complemented the sea-fish market held every Wednesday and Friday on Foss Bridge.

Straining under the weight of many houses and shops, Ouse Bridge gave way again in 1564. Twelve people and 12 houses perished. The repairs took many years to complete.

By the 19th century, a new bridge was needed. But the task of constructing firm foundations in the fast-flowing river defeated every engineer who tried - except Hiram Craven.

The Burnley-born engineer sank a number of bales of wool into the river to slow the flow before laying his foundations in 1810. Slowly - very slowly - the bridge was built. Ten years later it was finally finished, and it still stands today, carrying more traffic than could have been dreamed of by Craven.

The next bridge to be built was Lendal. It took more than 20 years of debate before construction began. Even after work got underway in 1860, the problems did not stop. In September the following year, a terrible accident occurred when one of the girders was being lowered into place.

According to the Illustrated London News, "it toppled over and fell on the inner girder, after a few seconds that fell on the next, till the whole mass was precipitated, like a child's toyhouse, on the ground and into the river. Five men were killed and some others were much injured."

As a result of the accident, the council hired a new bridge engineer, Mr Page of Westminster, who submitted fresh plans for a cast-iron bridge.

It finally opened in January 1863: the toll to cross was half a penny for foot passengers, a penny for animals and twopence for horse-drawn vehicles.

Skeldergate Bridge was also a 19th century creation. The need was identified in 1874, when a council report revealed that more than 800 people were using the Skeldergate ferry each day.

After several redesigns, a structure with a middle arch spanning 90 feet and an opening end arch of 30 feet was agreed. It was opened on New Year's Day 1881, and like Lendal Bridge, a toll had to be paid to cross it. Skeldergate's opening arch was believed to have been lifted for the last time in 1955. Motorised traffic brought about a need for new bridges in the mid-20th century. City engineer Charles Minter produced a paper on that topic in 1958.

"The most obvious result of too much traffic for too few bridges is a traffic hold-up, and that is precisely what happens in York," he wrote.

Traffic jams on Lendal Bridge and the others were becoming a real headache.

Mr Minter put forward a proposal to build Clifton Bridge and a new road to link Boroughbridge Road at its south west end and Clifton at the north east end. Plans were later submitted to the Ministry of Transport to build a bridge over the Ouse at Nun Ings, almost opposite Terry's factory, not far from where the Millennium Bridge now stands.

At the same time Castle Mills Bridge was widened to cope with the surge of car ownership.

Clifton Bridge was not Mr Minter's idea. The notion was first proposed in October 1913, when pressure on the Water End to Clifton ferry was growing. This, and subsequent schemes, were shelved due to cost. So the Army came in and built a bridge at Clifton. Soldiers constructed a 300-ton temporary Bailey bridge to cope with the extra traffic generated by the York Minster wedding of the Duke and Duchess of Kent in 1961.

Its effect on relieving traffic congestion was immediately apparent and its permanent replacement was finally sanctioned. Clifton Bridge, built of 4,000 tons of concrete and 50 tons of reinforced steel, was opened by the Lord Mayor of York, Archibald Kirk, on October 28, 1963. By the end of the decade, 10,000 vehicles a day were crossing the bridge - a figure that has been rising ever since.