The Aquarius rescue ship arrived in the Spanish port of Valencia on Sunday, after Italian authorities refused to allow the vessel to harbour in Italy for several days.
The Aquarius was seen docking behind the Italian coast guard ship, the Datillo, which was the first to arrive earlier on Sunday.
Inflatable dinghies found and rescued a total 629 migrants who were stranded off the coast of Libya at the weekend, transporting them to the safety of the Aquarius ship.
Earlier this week the Spanish government agreed to take in the migrants, including pregnant women and children, who were saved by the French charity SOS over the weekend.
Italy and Malta refused to let the boat dock in their ports, and so 250 people had to be transferred to the Italian Navy’s Orione and a further 274 to the Coast Guard’s Dattilo ship.