Sir Christopher Wren's Temple Bar marked the gateway to the City of London for 200 years. Then it retired to the country. And now, thanks to a £4m stone-by-stone removal job, the arch should see a few more centuries of capital life at Paternoster Square.
If stones could talk, the portland blocks of the last surviving gateway into the City of London could spin a few yarns. Temple Bar, commissioned by Charles II in 1669 and designed by Sir Christopher Wren, stood outside the Royal Courts of Justice in Fleet Street. In the 18th century, the top of its main arches was decorated with the heads of traitors displayed on spikes. Two hundred years later, after causing a the Victoria's unbearable traffic congestion (Charles Dickens referred to it as "that leaden-headed old obstruction" in the opening to Bleak House), it was bought by the banjo-playing wife of aristocratic brewer Sir Henry Meux and found a new home in Hertfordshire.

But a new chapter in the Temple Bar story is beginning. Now owned by the Temple Bar Trust, the 24 m high structure is on its way back to the City of London. This time, it will form the southern gateway to the Paternoster Square development, where it will be reunited with another of its father's works, St Paul's Cathedral.

The dismantling, removal and reconstruction is being handled by Cathedral Works Organisation, the specialist stonemasonry arm of contractor Geoffrey Osbourne. The task involves carefully numbering and cleaning each block, restoring any damage and then carefully reassembling Temple Bar to create the impression that it had never left town. "It is imperative that it keeps its historic appearance," says Bernard Burns, CWO's director. According to English Heritage, this is one of the most important moves of a scheduled monument for a century.

Monument to Dickensian London
The Temple Bar consists of a shallow main arch flanked by a small arch on either side. Above the main arch is a small room capped by a barrel-vaulted timber roof clad with lead. Wren's design included four large statues of royalty contained within niches on either side of the gateway, a reminder that Charles II wanted a royal edifice as much as a City monument. Classically detailed, the building has rusticated stonework at the lower levels, and the main arch is topped by a entablature sitting over pilasters.

Wren's design replaced a timber gate, one of eight into the City of London, the others being Aldgate, Aldersgate, Bishopgate, Cripplegate, Ludgate, Moorgate and Newgate. Temple Bar appears in history as a witness to the Peasants Revolt of 1381, the wedding of Anne Boleyn to Henry VIII, and Queen Elizabeth I's celebration of the defeat of the Spanish Armada. It survived the Fire of London in 1666, but had fallen into disrepair when Charles II insisted that it be rebuilt. He offered the City £1005 to pay for it; the final cost was £1500.

But by 1878, the new Temple Bar was severely constricting the roadway. The problem is still clearly visible as the sides of the arch are heavily worn from the impact of coaches. The Corporation of London decided it had to go so the road could be widened and, because of its historical importance, carefully numbered the stones and placed them into storage.

Hertfordshire gentility
The opportunity to impress the neighbours with something a little different was spotted two years later by Sir Henry and Lady Meux. She was a former barmaid who had married into an aristocratic brewing family, much against its will. The couple bought the arch from the corporation and reconstructed it in the garden of their Hertfordshire home, Theobalds Park. Craving respectability, Lady Meux used the room above the arch as a venue to entertain – and impress – her guests.

Lady Meux died in 1910 and Theobalds Park began a gentle decline. This change in fortunes had a detrimental effect on the Bar, which also suffered from a substandard reconstruction. "It wasn't rebuilt to the standard you would expect of that age," comments CWO's Burns, adding that it was "built to the standard of a [garden] folly" rather than a house. The stone also suffered because it spent more than 200 years in a smog-ridden London then 125 years in a damp forest. The four statues also became victims of vandalism. English Heritage removed them several years ago to prevent further damage.

The new Paternoster Square presented the opportunity to bring Temple Bar back to London. The Temple Bar Trust had been campaigning since 1976 to rescue the gateway from the neglect of Theobalds Park, and bought the arch from park owners the Meux Trust for the princely sum of £1. The Corporation of London agreed to foot the £4m bill for its removal and restoration. "It would have collapsed during the next 50 years; certainly large parts of the structure would have fallen off," says Burns. "It's definitely the right move."

Work on dismantling the gateway began in mid-October. CWO won the commission on the strength of its stonework expertise: for example, it is responsible for building the Diana Memorial. The first element of the contract was to gently clean the stone using a soft, dry abrasive, and to kill moss and lichen and prevent regrowth by applying a biocide to the stone.

Once scaffolding was erected, work started on a painstaking dismantling using traditional hand tools. The top of each stone was cleaned up and the mortar joints carefully chiselled away. Then the stone was numbered before being lifted away using a hoist attached to a tool called a Lewis pin. This has been used for hundreds of years, and is best described as a pair of tongs inserted into a hole drilled into the top of the stone. As the stone is lifted, the tongs are forced open to grip the sides of the hole.

Wren meets the 21st century
The cleaned-up stones are currently being stacked on pallets, packed with polystyrene to prevent damage and the whole pallet is then shrink-wrapped with plastic, ready for dispatch to Paternoster Square. By mid-December, most of the 500 pallets will have been prepared and the details of the contents typed into a spreadsheet in preparation for the reconstruction.

Damaged stones are sent to CWO's workshops in Chichester for restoration; only those beyond hope will be replaced. "Some of the stones have deteriorated so badly that they need stabilising before they are put back – unless they are structural," says Burns. Replacement stone for the missing parts of the statues will be carved, then stitched in.

Work on preparing the site in Paternoster Square has already begun. A plinth is being constructed, and scaffolding will be erected around it. The stones will be brought into the tight site and rebuilt using a feebly hydraulic lime mortar, which sets faster than non-hydraulic or hydrated lime. However, traditional hydrated lime will be used for repointing.

Decisions on whether to replace some stones with new material will be taken as the Bar is rebuilt. Because the stone is roughly sawn on each side apart from the dressed outer face, achieving level courses will be challenging.

  "We must ensure it is as level and plumb as possible," says Burns. "We also have to be aware this will be the fifth time the stone has been handled."

A few modifications will be incorporated into the rebuilt structure. Stainless steel tie bars will be used to stop the main arch spreading outwards. At Theobalds Park, it was buttressed by a Victorian lodge on one side and a wall on the other. "Joggles", traditional Y-shaped grooves for the mortar to bed into, will be cut into the vertical faces of the old stones so the structure is more monolithic.

One 21st century innovation is built-in fibre-optic and flood lighting. Completion is due November 2004, when Temple Bar should have moved into its latest home.