This palace is believed to have been built in the late 18th century and belonged to an aristocratic family, the Paes de Amaral (Viscounts of Alverca), thus becoming the Paes do Amaral Palace or Alverca Palace. In 1917, it was rented to a company that transformed it into the first casino: The Majestic Club.
The building underwent several changes under the direction of architect Silva Júnior, becoming a space for Lisbon's elite with its luxurious gaming rooms. In 2017, Mónica Queiroz, a technician from Lisbon's City Council, told Diário de Notícias that at the Majestic Club "(...) fortunes were made and lost in a single night (...)".
On the first floor of this casino, a stage separated the restaurant hall from the gaming room, adorned with sensual female figures, where "papillons who were tasked with keeping the men drinking and playing, spending money," also circulated, she further explained.
Meanwhile, the Majestic Club would be renamed "Monumental Club," closing in 1928. Not much later, in 1932, the Palace was leased to the Grémio Alentejano, which would be named Casa do Alentejo, becoming the headquarters of the Alentejo Regionalist Association. Finally, at the end of the 20th century, it was purchased from the descendants of the Paes de Amaral family, becoming the heritage of all Alentejo people.