On his travels he isn’t just seeking out a cheeky half of lager, he’s looking to get intoxicated. As one Pakistan businessman says to him: “Are you serious? Get drunk in Islamabad?”

On this subject, Osborne is deadly serious. Whilst most writers on drink shy away from examining their own less than healthy relationships with booze, the opening of the book sees Osborne getting the shakes whilst being interviewed for Italian television in a bar in Milan. It sets the tone for what follows as Osborne ploughs deeper into the Islamic world.

He begins his journey, naturally, in that most seductive of Eastern cities, Beirut, drinking wine with warlord-turned-vineyard-owner Walid Jumblatt (“thick juicy Americanised wine, more or less revolting”), Martinis in hotel bars and plenty of arak, the national drink of Lebanon.

From there it’s into territory where it’s far less easy to get a snifter or where alcohol is carefully cordoned off for Westerners as in Abu Dhabi, where Osborne gets spectacularly drunk and ends up fully clothed in the hotel swimming pool.

Today the Islamic world is notoriously proscriptive of alcohol, although the Qur’an is less clear on this than you might think. According to Tears of Bacchus: a History of Wine in the Arab World, the clearest anti-alcohol message comes in Surah 5:90-1: “Wine, gambling, idol-worshipping, and divination arrows are an abomination from amongst the acts of Satan.”

However the words are interpreted, alcohol was not always strictly controlled throughout Islam’s history. How could it be when Syria, Palestine, Lebanon, Iran and Iraq are the birthplaces of wine? Caliph al-Amin, who ruled from 809 to 813, was said to have a swimming pool of wine.

The wine-sodden, erotic poetry of his friend Abu Nuwas chronicles the nightlife of Baghdad. The other great Islamic bard of the vine was Omar Khayyam, after whom a brand of Egyptian wine is named.

This relative tolerance persisted until very recently as the great cities of the East like Alexandria, Cairo and Baghdad were cosmopolitan centres with large Christian and Jewish populations. Further east, Karachi was once famous for its nightlife.

Osborne writes: “alcohol was more or less freely sold and consumed [in Pakistan] from 1947 until 1977, when Prime Minister Zulfikar Ali Bhutto banned its sale”. Today it is now only available from hotel bars and specialist shops for foreigners and non-Muslims.

Osborne finds himself the lone drinker in a bar hidden in a hotel in Islamabad. The bartender tells him about Muslims trying to sneak in for a drink: “We are catching these blighters every week.”

There’s still a brewery and distillery in Pakistan called Murree, “drink and make Murree” as the advertising slogan says, set up to provide beer for British soldiers. It produces surprisingly good whisky, according to Osborne. They are not allowed to export it, so officially it is only drunk by non-Muslims within Pakistan.