Alaska was not much use for a ruler with no money to back serious colonialism or to exploit the military potential of a base on the Pacific coast of north America. Even though the Czars had held the land since 1741, the number of Russians living there never exceeded 400. These explorers and traders were now complaining about an influx of British and American settlers and Alexander did not want to be bothered with tiresome territorial squabbles. So the “For Sale” sign went up on the wilderness.

The man given the job of offloading the real estate was Baron Edouard de Stoeckl, Russia’s minister in America. He knew he was on to a winner. The US Secretary of State, William Seward, believed in Yankie expansion. The baron was authorised to accept $5 million, but suspected that Seward would offer more. He was right. Determined to push through the sale while the Congress was in session, Seward raised his offer to $7m. Eventually, after some quibbling on Stoeckl’s part, the final price was $7.2m in gold. This worked out at 2.5 cents per acre for a chunk of the globe twice the size of Texas.

Ironically, it was the American who was initially accused of blundering. He became the butt of popular jokes over “Seward’s folly”. Alaska was dismissed as “Seward’s icebox”.

No one understood why he had wanted the territory. Rumours of its vast natural resources and mineral wealth were largely ignored until the Klondike goldrush of 1897. These days, of course, it is black gold that matters. Nearly 90,000 barrels of oil slop along the trans-Alaska pipeline every hour. And the purchase was an important step on America’s rise as a great power in the Asia-Pacific region. Certainly, Seward regarded Alaska as the most significant act of his political career. What the Czar said is not on record.