#officialonedirectionus

Documents filed in the U.S. District Court in California allege that the U.K's One Direction learned they shared the name when they attempted to file with the U.S. Trademark Office.

"We were negotiating for about a month before we filed the complaint," the plaintiffs' lawyer, Peter Ross, told E! News. "In our view, negotiations had stalled and weren't going anywhere."

The one thing the two groups agree on : that they can't agree.

A spokesperson for the U.K.-based 1D said in a statement: "There is a dispute with a local group in California about the ownership of the One Direction name in the U.S.

One Direction's management tried to resolve the situation amicably when it first came to light, but the Californian group has now filed a lawsuit claiming they own the name. One Direction's lawyers now have no choice but to defend the lawsuit and the band's right to use their name."

The battle of the band names intensified in June 2012, when chart-topping boy band One Direction filed a countersuit against California's One Direction, alleging they actually had their name swiped by the U.S. group.

A statement from the better known 1D reads: "One Direction's lawyers have now had to file an Answer and Counterclaim in order to defend and assert the band's right to use their name. The Answer and Counterclaim makes it clear that it is One Direction (U.K.) who has prior rights to the name in the U.S., as it was One Direction who used the name in interstate commerce in the U.S. first."

The U.S. version of One Direction is fronted by Sean O'Leary. The pop group is not signed to a label but has been selling its album, The Light, on iTunes since February 2011. The Harry-Liam-Niall-Louis-Zayn - version of One Direction became the first U.K. band to debut at No. 1 on Billboard 200 with their first U.S. album, Up All Night.

While lawyers continue to arm wrestle over name rights, it's good to note this is hardly the first time two bands have gone to war over a name - a few memorable battles:

Two bands - one a group of young heart-throbs, the other a trio of Scottish 50-somethings - settled a 2003 court dispute with the agreement that both would continue to call themselves Blue

In 2005, Scottish inde rockers Eskimo Blonde demanded that a girl trio who found sudden fame on The X Factor change its name. The dispute was quickly resolved when the Liverpool girl group was eliminated from the televised talent show.

Rock band Pink Floyd has endured several name changes. One of the group's earliest names was Tea Set - until they found themselves playing in a big show with another band with the same name.

The Grateful Dead was once known as The Warlocks but was forced to change its name when another band called The Warlocks landed a record deal. Meanwhile, a third Warlocks group was playing up and down the East Coast. That band became Velvet Underground.