Established on the 5th of March in 1916 The club later became RCD Mallorca was registered at the Spanish Football Federation under the name of Alfonso XIII Foot-Ball Club.
A few weeks after its creation The club spent a short time in forming directors for Alfonso XIII FBC, headed by engineer Adolfo Vazquez Humasque, along with eight other football supporters. Their first stadium was that of the Buenos Aires field, was opened with a friendly match with FC Barcelona just 20 days after they had registered a further rapid development. Although the game ended in a disappointing defeat of 8-0 the game was just a few days before the King Alfonso XIII himself requested the official adoption of the term "Real" as the team's name which resulted in the name being changed to Real Sociedad Alfonso XIII Foot-Ball Club.
In 1917 in 1917, in 1917, the Catalan Federation granted Real Sociedad Alfonso XIII access to Second-tier League Championship, as an official champion of the Balearic Islands. In the championship final Los Bermellones went on to win their first title by claiming a convincing 3-1 win against Futbol Club Palafrugell, in Barcelona.
Through the 1930s the board of directors was able to organize games against peninsular teams like RCD Espanyol and Real Murcia and also hosted rare matches against foreign teams such as: Ajax in 1923, Uruguay's national team in 1925, Chilean outfit Colo-Colo in 1927, and one of the oldest teams in the Czech Republic, Prague Meteor, in 1930.
In 1931, following the creation by the Second Spanish Republic which prohibited any all reference to the monarchy, this club was renamed Club Deportivo Mallorca.
Even though major competitions and fixtures throughout Spain were interrupted due to the advent of Civil War in 1936, the team had a highly prosperous time, winning every championship they participated in and the football on the island was unaffected by the delays that were experienced across the nation. After the war ended and squads from Peninsula were soon to resume after which they were able to play again and the Second Division was inaugurated, comprised of five groups of eight players each.
It was during the Second Division during the Second Division that, on 22 September 1945, it was decided that the moment was right to say goodbye Buenos Aires Field and up sticks to Es Forti, a 16,000-maximum capacity stadium that would serve as home for more than 50 years and would undergo numerous expansions. The team of players such as forward Sebastian Pocovi, defender Saturnino Grech, and goalkeeper Antoni Ramallets defeated Jerez 3-1 in the first fixture of the new season on the same day, with Carlos Sanz scoring Es Forti's first goal in front of the packed terraces. The name Es Forti was short-lived however it was later renamed by the board, changing the stadium's name to Lluis Sitjar to honor the memory of the player who was responsible for the development of the field.
In the 1949-1950 time frame, the Balearic club was able to regain their "Real" name and changed it to Real Club Deportivo Mallorca
