A charter of liberties granted by Duchess Joan to Brabant on 3 January 1356, the Joyeuse Entrée entailed a codification of earlier customary rights in detailing the mutual obligations of the citizens of the duchy and their sovereign. It provided Brabanters with both the protection of a powerful duke and the preservation of rights guaranteed to the Estates, including administrative and fiscal liberties of municipalities. Sovereigns under the Burgundian, Spanish, and Austrian regimes swore to respect the Joyeuse Entrée in a formal ceremony, held first at Leuven and then, following transfer of the capital, at the Hôtel de Ville in Brussels, investing the ruler as duke of Brabant. It was abolished in June 1789.
The tradition continues following installation of a new monarch by parliament when the sovereign greets the public before the Palais Royal in a handshaking ceremonial.
Historical Dictionary of Brussels. Paul F. State.