that this was a crucial chance for Christendom. But in 1269 there was no Pope, as Clement IV had just died and the cardinals had yet to summon the energy to meet and choose his successor. The Polos had no choice but to go to Venice and wait until a Pope was elected. By the spring of 1271, despite mounting public indignation, the cardinals appeared to be no nearer reaching a decision. Seeing this, the Polos decided to return to Acre, this time with Marco. There they announced to the Legate that Pope or no Pope they were going to return to the Khan 'for we have already tarried long and there has been more than enough delay'. They set off east in the last days of August.
Meanwhile in Viterbo the papal election had turned into an international scandal. In order to speed a decision, the civic authorities had locked the cardinals in the Papal Palace, threatened a starvation diet and removed the roof to allow the divine influences to descend more freely on their counsels'. This unusual approach to the workings of the Holy Spirit proved a surprising success. The cardinals delegated the decision to a committee of six who, anxious to get away, elected Theobald that same day. A week later news of the decision reached Acre and the Polos were recalled. The new Pope immediately gave them permission to go to Jerusalem to fetch the Holy Oil. He also provided the expedition with, if not one hundred, then at least with two intelligent men of the Christian faith. Friar Nicolas of Vicenza and Friar William of Tripoli, the two most senior friars in the Holy Land. Pope Gregory gave to the friars extraordinary powers of ordination and absolution, and to the Polos letters and presents for the Great Khan. The party, now five strong - the two elder Polos, Marco, and the two friars - finally departed in early November.
At my primary school we knew all about Marco Polo. He wore a turban, a stripy robe a bit like a dressing gown and he rode a camel with only one hump. The Ladybird book which had this picture on the cover was the most heavily thumbed book on the school bookshelf. One day, my friends and I put some biscuits in a handkerchief, tied the handkerchief to a stick and set off to China. It was an exhausting walk as there were no camels in Scotland, and by tea time we had eaten all our biscuits. There was also the problem that we were not absolutely sure where China was. It was beyond England, of that we were certain, but then we were not absolutely sure where England was either. Nonetheless we strode off manfully towards Haddington where there was a shop. We could ask there, we said. But when it began to get dark we turned around and went home for supper. After consultation we decided to put the plan on the shelf for a while. China could wait.
In fact, no one had ever been much more successful than us in following Marco Polo. Many had, like us, set off in his tracks but no one had ever managed to complete the journey. In the nineteenth century Afghanistan was too dangerous; in the twentieth, first Sinkiang, then the whole of China was closed to foreigners. By the time China began opening up in the early eighties, Afghanistan was closed again, this time because of the Soviet invasion. Now, while the Soviets are withdrawing, Iran and Syria have both closed their borders. But in the spring of 1986 the opening of the Karakoram Highway, the mountain road which links Pakistan with China, made it possible for the first time, perhaps since the thirteenth century, to plan an overland route between Jerusalem and Xanadu and to attempt to carry a phial of Holy Oil from one to the other. The war in Afghanistan prevented the whole of Polo's journey being followed but in principle it was now possible to follow almost all of it, and to complete the journey. It was my then girlfriend Louisa who spotted the small article in the New York Herald Tribune which announced the opening of the highway and together we decided to mount an expedition to follow in the