Ross Finlay

In Land Rover's 50th

anniversary year, various celebrations and rough-country expeditions are planned

And the company has been tracking down the owners of its early products, which have given half a century of service.

The original vehicle,

introduced in 1948, was no

luxury job.

A previously staid British manufacturer had the idea of extending its market into four-wheel drive workhorses - taking advantage of the fact that postwar supplies of aluminium for body panels were more easily obtainable than steel, and that the government of the day was interested in anything which would generate export sales.

Its designers almost certainly never imagined that 50 years later there would be four model ranges. And the idea of 4x4s being classed as ''executive'' would have seemed absurd.

Another category might be called ''expedition'', because Land Rover products have been driven to some excessively out of the way locations.

Tom Stoppard, an ex-RAF test pilot now heavily involved in overland (which in this context means off-road) travel, has just written a book called Vehicle-dependent Expedition Guide.

Published with Land Rover's assistance, it covers everything about off-roading - from clothing to satellite navigation systems.

While the Defender is the modern expression of the original design, and the Freelander is marketed as a leisure vehicle, the Discovery and the Range Rover have long been accepted in the executive market.

In fact, the Range Rover was the first off-roader to seem at home in any situation - from clambering up muddy hillsides, to turning up at business meetings, or taking a smartly dressed party to the opera.

The Range Rover catalogue includes cars with four-litre and 4.6-litre V8 petrol engines, and 2.5-litre turbo diesels. There are luxurious fittings such as leather upholstery and walnut door cappings, and the top-rated HSE is very strongly specified.

If even the HSE equipment list seems too meagre, then Range Rover Autobiography offers a bespoke service by which items such as rear-seat television, lambswool rugs and a CARiN navigation system can be provided at obvious extra cost. However, underneath all this fancy stuff is a very competent off-roader. That half-century of experience has allowed the company's engineers to make the Range Rover a match for just about any opposition when it comes to tough mountain going.

Variable height air suspension is just one of the systems which keeps the Range Rover in the premium dual-purpose category.

It was the Range Rover which introduced many of them to the market in the first place.

One size down, the Land Rover Discovery was the

company's first 4x4 to go ''lifestyle''. Terence Conran was consulted on the interior design, which is ingenious in its details.

A stepped roofline also gives the Discovery more rear cabin space than many of its rivals.

The latest models feature 3.9-litre V8 petrol and 2.5-litre turbo diesel engines, as well as a better range of exterior colours and uprated interiors.

But, like the Range Rover, the Discovery is still a properly engineered off-roader.

It may that few Discovery owners ever venture into rough terrain, but for those who do the versatility is there.

The next generation Discovery is due in November, keeping the same model name but moving up-market.

Land Rover promises that its specification will include all the latest 4x4 technology, such as traction control, active ride

control and hill descent control.