Seeking inspiration from German reunification, U2 began recording "Achtung Baby" at Berlin's Hansa Studios in October 1990. The sessions were fraught with conflict, as the band argued over their musical direction and the quality of their material. After tension and slow progress nearly prompted the group to disband, they made a breakthrough with the improvised writing of the song "One". Morale and productivity improved during subsequent recording sessions in Dublin, where the album was completed in 1991. To confound the public's expectations of the band and their music, U2 chose the record's facetious title and colourful multi-image sleeve.