IT'S 50 years since Jaguar launched the XJ saloon and while the car may have changed significantly over eight generations it remains the flagship of the Fast Cat brand.
And to mark half a century of production the British car maker is releasing a special edition run of XJ50 models - decked out to the nines.
Like all other versions of the XJ on sale in the UK it is diesel only and powered by a 3.0-litre V6 developing a healthy 300ps.
Priced from £74,280 in short wheelbase form or £77,280 for the long wheelbase model we tried, it is sumptuously equipped and sits at the top of the current XJ line up.
Jaguar first introduced diesels back in 2003 on the now defunct X-Type and since then they have featured in all its saloons and estates and the latest is as clean as they come with emissions of just 155g/km.
Compare that to the 264g/km CO2 rating of the 5.0-litre V8 version of the XJ and the difference in fuel economy is obvious. The XJ50 has an official fuel figure of 48 miles per gallon - and that's almost twice as many miles per tank as you would get from the V8.
Real world use saw an average return close on 40mpg from the XJ and it's no slouch either with a 0 to 60 time of 5.9 seconds and a maximum of 155mph.
The XJ50 is based on the Premium Luxury version of the XJ and comes with the likes of quilted soft leather upholstery, heated and cooled front seats, privacy glass and plenty commemorative reminders of its lineage such as illuminated XJ50 kickplates.
Other distinctive features include front and rear bumpers from Autobiography models, 20-inch alloys and XJ50 badging on the boot and front wings.
There's also a high end 825 Watt Meridian surround sound system, blind spot and reverse traffic warnings and a 360 degree parking camera set up while in the back the XJ50 has a fold-down central armrest, individual air conditioning controls and fold out display screens and picnic tables.
Options on the XJ50 we tried included an upgraded sound system at more than £4,000, a dual view touchscreen at £615 and parking assist technology which added another £1,190 taking the total to a heady £90,625.
That places the special XJ well and truly in luxury limousine territory and for a car that was first seen almost 10 years ago it can still hold its own against the likes of the Mercedes S-Class and Audi A8.
That said, the XJ is showing its age and a new model which is likely to include electric power is in the wings.
With Jaguar and sister brand Land Rover having to compete in a market that has seen a sharp reduction in diesel sales and a slump in global demand such a power option is vital.
Nevertheless, the XJ50 is a splendid example of the company's expertise.
What started back in September 1968 with the first XJ went on to spawn the second generation model in 1973, the third in 79, the XJ40 in 86 to be followed in the 90s with the X300, the X308 in 98 and the X35d in 2003 before the arrival of the current X351 in 2009.
The XJ has become a marker for British innovation. Over the years it has been the world's only mass-produced 12-cylinder four-door car and, with a top speed of 140mph it was also the fastest four-seater of its time.
The Series 2 was the first to offer a two-door coupe model in 1975 and the XJ40, in production for eight years from 1986, introduced the celebrated ‘J' gate gear shifter and self-levelling suspension.
An aluminium monocoque bodyshell helped reduce the XJ's weight by 40 per cent from 2003, before the current XJ model brought additional technologies such as all-wheel drive and a virtual instrument cluster.
And its success has not been confined to the road appearing in a number of hit movies including Love Actually, The Long Good Friday and in James Bond films.
As Ian Callum, Jaguar's design director who created the current model, said: "Spanning half a century, the Jaguar XJ remains true to its heritage with a wonderful balance of beautiful design, intelligent performance and indulgent luxury that ensures it stands out from the crowd. This is a car worth celebrating and the XJ50 pays homage to a giant within the Jaguar brand that we believe is one of the world's most stylish sporting saloons."
That all puts the big Jaguar saloon in an enviable position of being loved by the rich and famous as much as the everyday driver and business executive - qualities the new XJ is sure to embody.