WHAT are called "British Residences" are the homes abroad for our Ambassadors and High Commissioners.

Some are pretty functional; but some, it has to be said, are grand, reminders of Britain's imperial past and the fact that in diplomacy, size matters.

I write this from one of the grandest of our Residences, in the heart of Moscow. It's a huge mansion built at the end of the 19th century by a rich magnate who had made a fortune from sugar beet.

He was the son of a serf - a slave. Slavery of Britons by other Britons in Britain was abolished in the middle ages. In Russia, serfdom was still going strong as Britain was at the height of its industrial power, and more and more Brits were getting the vote. It took a decision by the Tsar Alexander II in 1861 to abolish it.

We took over the mansion in the 1930s; and from then until 2000 it acted both as the home of our Ambassador, and as the Embassy (i.e. the office) as well.

Lord knows how everyone fitted in. But these days, the Embassy has its own, new purpose-built headquarters, and the Residence is back to its original use.

Inside, it's a queasy mixture of architectural styles, Gothic, Baroque, and Muscovite with a bit of French imperial thrown in. The entrance hall is like a set from one of the House of Horror movies: high ceilings, gloomy, dark elaborately-carved staircase and panelling. I was expecting a pair of bats to swoop on me at any moment.

The greatest thing about the mansion is the view. It's spectacular. One of the finest in the world. It looks straight out over the Moskva river to the Kremlin, a centuries old fortress developed into a vast palace by a succession of Tsars.

So you see golden onion-domes atop the Orthodox churches, resplendent government buildings alongside. The interiors are pretty good too.

The very late abolition of slavery, and the other failures of the Tsarist regimes to absorb the strong social and political pressures of the late 19th, were among the factors which led to two revolutions in the early 20th Century. The first in 1905 was crushed but the second in 1917 was successful and led to the establishment of the Communist Soviet Union taking in not just Russia, but many other nations to the east, south and west.

Today, the Soviet Union is no more. Its collapse in 1991 led to the rebirth of countries like Estonia, Latvia, Ukraine, Georgia, Kazakhstan and many others.

There were over 250 million in the old Soviet Union. In the Russian Federation the population is not much more than twice the UK's (143 million compared to 60 million), for a land mass seventy times the UK's area.

The sights I saw in Moscow were, sadly, incidental to my trip. Its purpose was discussions with Sergei Lavrov, the new-ish Foreign Minister and Igor Ivanov, an old friend who had been Foreign Minister but is now ensconced in the Kremlin as President Putin's national security adviser (equivalent to the USA's Condoleezza Rice). The UK is the largest foreign investor in Russia. Bilateral contacts - tourist, family, and business - are increasing week by week.