Answer by taking a quote from the following article:

Joy Division were an English post-punk band formed in 1976 in Salford, Greater Manchester. Originally named Warsaw, the band consisted of singer-songwriter Ian Curtis, guitarist and keyboardist Bernard Sumner, bass player Peter Hook and drummer Stephen Morris. The band was formed by Sumner and Hook after attending a 4 June 1976 Sex Pistols concert at the Lesser Free Trade Hall in Manchester. While Joy Division's early recordings were heavily influenced by early punk, they evolved a unique sound, aided by producer Martin Hannett, which earned their reputation as pioneers of the post-punk movement.

Despite their short career, Joy Division have exerted a wide-reaching influence. John Bush of AllMusic argues that Joy Division "became the first band in the post-punk movement by [...] emphasizing not anger and energy but mood and expression, pointing ahead to the rise of melancholy alternative music in the '80s."  Joy Division have influenced bands as diverse as contemporaries U2 and the Cure to artists such as Radiohead, Nine Inch Nails, Neurosis, Interpol, Bloc Party, the Editors and rap artists. Rapper Danny Brown is known to have named one of his albums after the Joy Division song "Atrocity Exhibition", whose title was partially inspired by the 1970 J. G. Ballard collection of condensed novels of the same name. In 2005, both New Order and Joy Division were inducted into the UK Music Hall of Fame.  The band's dark sound, which Martin Hannett described in 1979 as "dancing music with Gothic overtones", presaged the gothic rock genre. While the term "gothic" originally described a "doomy atmosphere" in music of the late 1970s, the term was soon applied to specific bands like Bauhaus that followed in the wake of Joy Division and Siouxsie and the Banshees. Standard musical fixtures of early gothic rock bands included "high-pitched post-Joy Division basslines usurp[ing] the melodic role" and "vocals that were either near operatic and Teutonic or deep, droning alloys of Jim Morrison and Ian Curtis."  Joy Division have been dramatised in two biopics. 24 Hour Party People (2002) is a fictionalised account of the rise and fall of Factory Records in which members of the band served as supporting characters. Tony Wilson said of the film, "It's all true, it's all not true. It's not a fucking documentary", and that he favoured the "myth" over the truth. The 2007 film Control, directed by Anton Corbijn, is a biography of Ian Curtis (portrayed by Sam Riley) that uses Deborah Curtis's biography of her late husband, Touching from a Distance (1995), as its basis. Control had its international premiere on the opening night of Director's Fortnight at the 2007 Cannes Film Festival, where it was critically well received. That year Grant Gee directed the band documentary Joy Division.

is there one main legacy here?
Joy Division have influenced bands as diverse as contemporaries U2 and the Cure