It is still not fully known what led to the events on 17 and 18 August last year when a total of sixteen civilians lost their lives in the deadliest terror attack to occur in Barcelona since the 1987 Hipercor bombing.
On the afternoon of the 17th, 22-year-old Younes Abouyaaqoub drove a rented white Fiat Talento van on the pavement of La Rambla, zigzagging at high speed and crashing into pedestrians for about 550 metres before the vehicle ground to a halt on the Joan Miró mosaic. In the attack, Abouyaaqoub killed 13 people and injured at least 130 others, one of whom later died. Abouyaaqoub then fled the scene on foot before stabbing another to death in order to steal their car to make his escape.
Nine hours later, five men thought to be members of the same cell drove into pedestrians in nearby Cambrils, killing a 63-year-old Spanish woman and injuring six others during a subsequent knife attack. The men, Houssaine Abouyaaqoub, Omar Hichamy, Mohamed Hichamy, Moussa Oukabir and Said Aalla were all shot and killed by police on the scene.
Three days later, on 21 August, police shot and killed the La Rambla attacker Younes Abouyaaqoub near a petrol station in Subirats, about 40 kilometres from Barcelona, after a woman called police after spotting a man which fit his description. According to the Mossos d'Esquadra regional police force, he had "an explosive belt attached to his body" at the time.
Subsequent investigations showed that the cell's plans were much greater than those which transpired. The night before the La Rambla attack, an explosion occurred in a house in Alcanar, destroying the building and killing two members of the terrorist cell, including imam Abdelbaki Es Satty, thought to be the mastermind.
The home had over 120 gas canisters inside which police believe the cell was attempting to make into large bombs to attack the Sagrada Família church.
The attacks were the deadliest in Spain since the March 2004 Madrid train bombings, with 16 people of ten nationalities killed and over 130 people from over 34 nations injured.
The day after the attacks, a minute's silence, led by King Felipe VI, was observed at Plaça de Catalunya, which ended with chants of "No tinc por" ("I am not afraid"). On 26 August, a large crowd marched down the Passeig de Gràcia in a protest against the terror attacks. Some people booed the King, blaming him for arms sales. King Felipe is expected in Barcelona today for the first anniversary commemorations.