Jaguar XJ: the series that carried the company (1968–2009) The Jaguar XJ series began in 1968 as the saloon that replaced Jaguar's entire range and stayed the company's flagship for four decades. This overview decodes the family, Series 1 to 3, the coupe, the XJ40 and the X300/X308, links to our detailed guides on each, and explains which classic XJ suits which buyer.