Walter

In the build-up for the NXT UK and NXT co-branded pay-per-view, Worlds Collide, Imperium began feuding with The Undisputed Era (NXT Champion Adam Cole, Roderick Strong, and NXT Tag Team Champions Bobby Fish and Kyle O'Reilly), which was further intensified during the closing moments of NXT UK TakeOver: Blackpool II on January 12, 2020, when the group attacked Imperium following Walter's successful title defense against Joe Coffey. During his reign the following week, the WWE United Kingdom Championship was renamed to NXT United Kingdom Championship and he was presented with a slightly updated belt design, replacing the WWE logo at the center with the NXT UK logo.

During the 2019's edition of Super Strong Style 16, Walter defeated Trent Seven in a title vs title match, winning Seven's Progress Atlas Championship. At Chapter 95: Still Chasing, Walter lost the Progress Unified World Championship when Eddie Denis successfuly cashed in his title opportunity gained by defeating Mark Andrews at Chapter 76. This was a triple threat match also involving David Starr.

On 12 January 2019 at NXT UK TakeOver: Blackpool, Walter made his WWE debut by confronting WWE United Kingdom Champion Pete Dunne after Dunne's successful title defense.

The following week Walter confronted Pete Dunne and Joe Coffey in ring. Although he did not say anything, he made his intentions for Dunne’s WWE UK Championship quite clear. On the edition of 2 February 2019 of NXT UK Walter made his in ring debut against Jack Starz. He beat Starz in under four minutes. At NXT TakeOver: New York, Walter defeated Dunne to win the United Kingdom Championship, ending Dunne's record setting reign at 685 days.

In January 2018, Walter unsuccessfully challenged for the PWG World Tag Team Championship with Ringkampf partner Timothy Thatcher, losing to the defending Chosen Bros (Jeff Cobb and Matt Riddle). On 21 April 2018, Walter defeated champion Keith Lee and Jonah Rock in a three-way match to win the PWG World Championship. Walter later lost the title to Jeff Cobb on 19 October.

It was announced that Walter was going to be added to the Defiant Internet Championship match of David Starr against Travis Banks at Lights Out. However Banks didn't compete due to a foot injury. Instead Walter would later defeat Starr to become the #1 Contender for Banks' title, which would end in a draw at No Regrets. On 2 June, Walter defeated Banks and Zack Sabre Jr. to win the Defiant Internet Championship. On 30 December 2018, Walter lost the title to Martin Kirby.

Walter debuted in Evolve at Evolve 90 on 11 August 2017 in Joppa, Maryland, defending the Progress Atlas Championship against Fred Yehi.

Walter unsuccessfully challenged for the WWN Championship the next night at Evolve 91 in New York City in a Four Way match that also involved Matt Riddle, Keith Lee, and Tracy Williams. He again made an unsuccessful challenge for the WWN Championship on 9 December 2017 when he was defeated by Lee at Evolve 96 in New York City.

Walter made his Pro Wrestling Guerrilla (PWG) debut by entering the 2017 Battle of Los Angeles tournament, where he was eliminated by eventual finalist Keith Lee in the opening round. He was then defeated by Ricochet at All Star Weekend 13 - Night One. The next day, he got his first PWG victory by defeating Zack Sabre Jr. in a match that was awarded a five-star rating by Dave Meltzer in the Wrestling Observer Newsletter.

Walter participated in the tournament to determine the inaugural Progress Atlas champion in 2016 but he finished the tournament with 2 points. At Chapter 47, Ringkampf (Walter, Axel Dieter Jr. and Timothy Thatcher) challenged British Strong Style (Pete Dunne, Trent Seven and Tyler Bate) for all of their championships, in a six man tag team match, unsuccessfully challenging all of them. He defeated Matt Riddle to win the Progress Atlas Championship at Chapter 51: Screaming For Progress at the O2 Academy Birmingham. He lost the title to Riddle a little over a month later on a Progress card in New York City, but recaptured it at Chapter 55: Chase The Sun at Alexandra Palace in a Three Way match that also involved Matt Riddle and Timothy Thatcher. At Chapter 68: Super Strong Style 16 Tournament Edition 2018, Walter vacated the Atlas title in order to chase the PROGRESS world title, held by Travis Banks. At Chapter 74: Mid Week Matters, he defeated Banks to win the title.

On 24 May 2015, Walter debuted as Big Daddy Walter in Progress Wrestling at the 2015 Super Strong Style 16 Tournament at the Electric Ballroom in London, losing to Rampage Brown in the first round. The two met again later in 2015 at Chapter 23: What A Time To Be Alive! in a match notable for the ring breaking after Brown was whipped into the corner. He entered the Super Strong Style 16 Tournament again in 2016, reaching the quarter-finals before being eliminated by Chris Hero.

Walter and partner Robert Dreissker defeated RockSkillet (Jay Skillet and Jonathan Gresham) to win the wXw World Tag Team Championship at day three of 16 Carat Gold on 3 March 2013. They would later lose the titles in Hamburg, Germany to Hot and Spicy (Axel Dieter Jr. and Da Mack). He partnered Zack Sabre Jr. to win the vacant wXw World Tag Team Championship on 4 October 2015 in the finals of the 2015 World Tag Team Tournament, but relinquished the title at the wXw Fifteenth Anniversary Show on 12 December 2015, losing to Cerebrus (Ilja Dragunov and Robert Dreissker). Walter and Ringkampf stablemate Timothy Thatcher defeated Massive Product (David Starr and Jurn Simmons) to win the wXw World Tag Team Championship in the finals of the 2017 wXw World Tag Team League on 8 October 2017. On 11 March Walter and Thatcher lost the wXw Tag Titles to Da Mack and John Klinger.

Walter made his Westside Xtreme Wrestling debut on 4 May 2007, in a match that also involved Atsushi Aoki, Adam Polak, and Tengkwa on the pre-show at the 16 Carat Gold Tournament. He defeated Zack Sabre Jr. to win the wXw Unified World Wrestling Championship on 2 October 2010 in Oberhausen, Germany. He lost the title to Daisuke Sekimoto on 15 January 2011, but won it back later that year on 2 May 2011, during a Big Japan Pro Wrestling card in Tokyo, Japan. He would then hold the title for 383 days, before losing it to El Generico on 19 May 2012. In the early May 2012 Big van Walter was defeated by Yoshihito Sasaki in a match to crown the inaugural BJW World Strong Heavyweight champion in Yokohama, Japan. He won the title for a third time on 27 July 2014, defeating Tommy End at Fans Appreciation Night, but lost it to Karsten Beck on 17 January 2015.

Walter Hahn (born 20 August 1987) is an Austrian professional wrestler and trainer. He is currently signed to WWE, where he performs on the NXT UK brand mononymously as Walter (usually stylised in all-caps as WALTER). He is the leader of the Imperium stable featuring Marcel Barthel, Fabian Aichner and Alexander Wolfe, and is the current NXT United Kingdom Champion in his first reign.