A photograph of traditional Irish musicians and dancers performing in Nazi, Germany, along with a thank you note, has been found in a souvenir album in Munich. The album will be auctioned next month in Germany.

In July 1936, the Irish group performed during a week-long conference in Hamburg that was hosted by ‘Kraft durch Freude’ (Strength through Joy), a Nazi organization created to boost workers’ morale by offering them leisure activities, popular entertainment, and holidays.

The album in which the photograph was found belonged to the family of Rudolf Hess, the deputy führer to Adolf Hitler. Hess was patron of the conference, named ‘Weltkongress für Freizeit und Erholung,’ which took place a week before the summer Olympic Games in Berlin. Minister for propaganda Joseph Goebbels and Hermann Goering, founder of the Gestapo and head of the Luftwaffe, also attended the event.

Ireland was one of 20 countries that sent delegations to the conference, the Irish Times reports.

The delegates paraded with traditional German dance groups through the streets of Hamburg, which were festooned with swastikas. The Irish musicians and dancers performed jigs and reels during the festival, giving performances they described to the Germans as “ceoil agus rince na h’Éireann.”

The delegations were all asked to contribute to a souvenir album for Hess at the end of the conference.

According to the Irish Times, the album contains a double page devoted to “Irland,” and includes a hand-painted illustration of the Irish Tricolor along with a thank you message to Hess handwritten in the Irish language and a typed German translation. There is also a photograph of seven of the members with a man playing the uilleann pipes, another one playing the fiddle, and five dancers, four women and one man, wearing kilts.

Members of the Irish group, which may have also included administrators and translators, signed their names in Irish: Liam Ó Flainn [Flynn], Seán Ó Diómsaigh [Dempsey], Ruaidhrí Ó Conchubair [O’Connor], Piaras Bhínseanlí [Winstanley], Lil Ní Chomarcúin [Comerton], Shighle Ní Meachair [Maher], M Ní Choinnigh [Kenny], Lil de Paor, [Power], Síle Ní Chinse [Clinchy] and Eibhlín Nic Canna [McCann].

The event, which cost 2 million Reichsmarks, was declared a success by the Nazi regime. In his closing address to the event, Goebbels stated that the entire world was “intoxicated by Germany.”

The album will be auctioned in Munich at the Hermann Historica auction house, which specializes in military memorabilia.

The auction house said the  starting bid for the album will be €1,300 ($1,620).