The construction of the Berlin Wall in August 1961 and the sealing of borders by the East Germans made Adenauer's government look weak. Adenauer chose to remain on the campaign trail, and made a disastrous misjudgement in a speech on 14 August 1961 in Regensburg when he engaged in a personal attack on the SPD Mayor of West Berlin, Willy Brandt saying that Brandt's illegitimate birth had disqualified him from holding any sort of office. After failing to keep their majority in the general election on 17 September, the CDU/CSU again needed to include the FDP in a coalition government. Adenauer was forced to make two concessions: to relinquish the chancellorship before the end of the new term, his fourth, and to replace his foreign minister. In his last years in office, Adenauer used to take a nap after lunch and, when he was traveling abroad and had a public function to attend, he sometimes asked for a bed in a room close to where he was supposed to be speaking, so that he could rest briefly before he appeared.