Some months after the Lancia Delta HF 4WD's introduction, at the end of the 1986 season, Group B rallying was terminated after a string of fatal accidents, and Group A took over as the World Rally Championship class.  Although not originally developed with rallying in mind, the Lancia Delta HF 4WD provided a suitable basis for the company to build a Group A rally car. The car was introduced for the 1987 World Rally Championship season, scoring 46 WRC victories overall and winning the constructors' championship a record six times in a row from 1987 to 1992, making Lancia the most successful marque in the history of the WRC and the Delta the most successful car. After the HF 4WD, Lancia had continued to evolve its Group A racing cars along with the road going versions such as the HF Integrale 16v, and the Evoluzione 1.  The Evoluzione 1 Delta, introduced for 1992, won the championship for a record sixth year in succession, before Lancia withdrew from the sport at the end of an unsuccessful 1993 season.