The Aquarius migrant ship, which has been at the core of a major migration dispute in Europe, docked in Spain on Sunday.
The 630 migrants, who earlier this week were turned away by Italy began disembarking at Valencia harbor.
The first of three ships transporting the group, an Italian coast guard vessel called the Datillo, pulled into the harbor just before 6:30 am (0430 GMT) with 274 migrants on board, according to the Red Cross.
The Aquarius itself pulled into port some four hours later.
The third boat, the Italian navy ship the Orione, was due to arrive late on Sunday, regional authorities said.
After the first boat docked, medical staff wearing white overalls, gloves and masks went on board to carry out initial medical checks before the migrants disembarked in groups of 20.
The migrants, most of them from Africa, were welcomed by a team of more than 2,000 people, including 470 translators and 1,000 Red Cross volunteers who distributed basic items such as blankets, clothes and hygiene kits
High waves and winds had forced the naval convoy to take a detour on its 1,500-kilometer (930-mile) voyage to Spain, ending a week-long odyssey in the Mediterranean.
The Aquarius, operated by the aid groups SOS Mediterranee Sea and Doctors Without Borders, was stuck off the coast of Sicily on June 9 when Italy refused it permission to dock and demanded that Malta do so. Malta also refused.
After days of bickering and food and water running low on the rescue ship, Spain stepped in and offered to grant the rescue boat entry.
David Noguera, the head of Doctors Without Borders in Spain, said he was glad that Spain allowed these migrants in but he is worried that more European nations will close their ports to those rescued at sea in the future.
"I have mixed feelings," he told The Associated Press on Sunday as the first boat arrived. "I am happy that the journey (for the Aquarius migrants) is over — a journey that was too long — and I am worried for the situation in the Mediterranean and the closing of European ports."
Among the passengers are 450 men and 80 women -- at least seven of them pregnant -- as well as 89 adolescents and 11 children under the age of 13, figures released by the Valencian authorities show.
They come from 26 countries, mainly from Africa but also Afghanistan, Bangladesh and Pakistan, MSF said.
Those with injuries -- mainly scratches and burns -- were taken to hospital along with the pregnant woman, local health officials said.
Red Cross Secretary General Elhadj As Sy thanked Spain "for opening their arms at times when many reject and are not showing solidarity."
"We call on all other countries to follow suit in helping those in need," he told AFP in Valencia.
The Aquarius rescued the migrants off Libya's coast last weekend but Italy's new populist government and Malta both refused to let it dock, accusing each other of failing to meet their humanitarian and EU commitments.
Spain eventually stepped in and agreed to receive the refugees as a "political gesture" to "oblige Europe to forge a common policy to a common problem," Foreign Minister Josep Borrell said.
Spanish authorities said they will examine the migrants case-by-case to see who may qualify for asylum.
Madrid on Saturday said it had accepted an offer from France -- who had angered Rome by branding it irresponsible -- to welcome Aquarius migrants who "meet the criteria for asylum".
Prime Minister Pedro Sanchez thanked French President Emmanuel Macron for his gesture, saying it was "exactly the kind of cooperation Europe needs" at this hour.
The plight of the Aquarius has again highlighted the failure of EU member states to work together to deal with the influx of migrant arrivals since 2015.
After Rome's decision to ban the Aquarius, Macron and Italian premier Giuseppe Conte met on Friday and agreed that the EU should set up asylum processing centers in Africa to prevent "voyages of death".
They also demanded "profound" changes to the EU's asylum rules which put the migrant burden on their port of entry to Europe -- mainly Italy and Greece.
