After the 1929 January 6th Dictatorship , in 1931 the kingdom became a constitutional monarchy .
The National Assembly became the National Representation consisting of the National Assembly ( lower chamber ) and the Senate ( upper chamber ) .
After the 1929 January 6th Dictatorship , in 1931 the kingdom became a constitutional monarchy and the National Assembly became the National Representation consisting of the National Assembly ( lower chamber ) and the Senate ( upper chamber ) .