On 27 September, thousands marched from the Atocha/Cuesta de Moyano area to Puerta del Sol, where they joined the housing camp already occupying the square.
Protesters chanted "inquilinas y estudiantes unidas y adelante" and "sin educación y vivienda no hay futuro". Their message brought together two demands: action on the housing crisis and support for public education.
The Delegación del Gobierno estimated the education march at about 10,000 people. Other reports put the crowd at as many as 20,000.
Hundreds stayed at the camp overnight, AFP and other reports said. The camp grew after a housing protest against the eviction of 87-year-old Maricarmen Abascal.
Both causes now share one square.
The housing camp has kept Puerta del Sol at the centre of the dispute. The education march brought students and public services into the same mobilisation. Protesters are pressing Madrid's regional government and Spain's national government to meet their demands.
The earlier housing demonstration drew about 25,000 people, information from the Delegación del Gobierno. Organisers said the turnout was substantially higher.
The camp is calling for stronger tenant protections, including safeguards against evictions without alternative accommodation, as well as indefinite rental contracts. Sindicato de Inquilinas representative Alicia del Río called the camp a "success" and said people were ready to stay until there was progress.
Organisers have said the camp could stay at least through Tuesday's Council of Ministers meeting. That gives the protest a near-term deadline.
Madrid City Council has also joined the dispute. The Ayuntamiento de Madrid accused the Delegación del Gobierno of "dejación de funciones", or failing to carry out its duties, during protests in central Madrid.
The education march joined the camp at Sol, turning the square into a shared platform for housing and public education demands.
An earlier housing report described how the square became a pressure camp after the mass march. Sunday's arrival brought another group and a new policy demand, while keeping the focus on housing measures.
Based on the information available, neither administration has announced new measures.
