Ai Weiwei's documentary Human Flow presents the problem in a globalized context. The Chinese artist aims to draw attention to the refugees' plight, and generate compassion for them. His documentary premiered at the Venice Film Festival and is now released in Germany.

The title of the film The Boat is Full (1980) has become idiomatic. In this movie, Swiss director Markus Imhoof depicted the fate of six people who had fled from the Nazi regime. At the time, films about refugees were typically set in the context of a historical conflict.

Many European films featuring refugees describe the fate of people fleeing to Europe. In comparison, there are way less movies set in Africa, dealing with the causes of flight and migration. In Hotel Rwanda (2004), director Terry George from Northern Ireland focuses on an episode of the Rwandan genocide from 1994.

Two years ago, Greek director Panos Karkanevatos shocked audiences with his film Riverbanks. Here, refugees taking off from Turkey with the aim of reaching Greece have to face several problems at once at the border river Evros. Smugglers exploit their situation, and the region has been mined during earlier conflicts between Turkey and Greece.

The French film Welcome (2009), by director Philippe Lioret, focuses on the fate of an Iraqi-Kurdish boy who wants to cross the Channel to Britain. Another character in the film is a French swimming teacher who supports the boy. It's a moving drama on humanity and friendship.

Like his colleague Philippe Lioret, Finnish director Aki Kaurismäki tells the story of a refugee boy trying to get from France to Britain. In Le Havre (2001), Idrissa from Gabon makes the acquaintance of an older and unsuccessful writer. And like in Welcome, the film depicts how a relation develops between the man and the boy.

In 2017, the Finnish director moved his audiences once again with a heartwarming film on the same topic. The Other Side of Hope premiered at the Berlinale. The protagonist is a Syrian refugee stranded in Helsinki. In scenes showing an encounter between Khaled and textile merchant Waldemar, the film showcases Kaurismäki's typical bizarre sense of humor.

Last year, German director Simon Verhoeven daringly approached the difficult topic with a satirical touch. His comedy turned out to be a hit in the country dealing with a strong influx of refugees. Willkommen bei den Hartmanns (Welcome to the Hartmanns') tells the story of a German family which has welcomed a refugee in their home.

Long before the current debates about the refugee crisis emerged, German director Andreas Dresen shot his film Nightshapes in 1999. It's all about a German businessman encountering a young refugee boy from Angola in Berlin. The latter immediately starts to cling to the old man, initiating an unusual friendship.

Two years ago, French director Jacques Audiard was awarded a Palme d'Or in Cannes for his refugee drama Dheepan. It tells the story of a family from Sri Lanka that has found a new home in France, in a rough Parisian suburban housing project. The refugees face another type of conflicts in their new home.

The film Mediterranea from 2015 shows what two African refugees have to go through shortly after their arrival in Europe. American-Italian director Jonas Carpignano depicts the fate of two friends, Ayiva and Abas from Burkina Faso, who made it to southern Italy, where they face more hostility and violence.

Last year, Italian director Gianfranco Rosi shocked viewers at the Berlinale with his documentary Fire at Sea. The winner of the Golden Bear depicted the fate of refugees fleeing across the Mediterranean to Europe. Some of them die along the way. Although Ai Weiwei's Human Flow is more ambitious in its expanse, critics found this documentary more convincing.

Ai Weiwei knows what it means to be a refugee. He was persecuted in his homeland China. His fall 2017 show in New York deals with the global refugee crisis through artwork distributed over the city's five boroughs. One of the largest of his installations, entitled "Gilded Cage," is located on the edge of Central Park (above). It invites viewers to enter and exit it by passing through turnstiles.

His largest work to date, "Law of the Journey," is a 70-meter-long inflatable boat with 258 faceless refugee figures that was shown in Prague. Ever since he moved to Berlin in 2015, Ai Weiwei has worked on numerous projects related to the plight of refugees, often meeting them personally. His documentary "Human Flow" was up for the Golden Lion Best Film award at the 2017 Venice Film Festival.

In late 2015 the image of 3-year-old Syrian refugee Alan Kurdi washed up lifeless on a beach made headlines around the world. In January 2016, Indian news magazine India Today published the above image of Ai Weiwei on the Greek island of Lesbos. While some praised the image as artistic activism, not everyone found the visual protest against European refugee politics ethically acceptable.

The exhibition "Luther and the avant-garde" features contemporary art. According to the 16th century religious reformer himself, images are neither good nor bad; they can inspire belief and prompt contemplation of God. Martin Luther's perspective on artistic freedom paved the way for modern art. Above, Ai Weiwei displays his take on individuality, religion and resistance in the exhibition.

In 2015, Lego refused to deliver Ai Weiwei a bulk order of the toys on political grounds. Supporters around the world sent millions of pieces in protest. Ai had already used Legos for a work of art on freedom of expression, shown in the abandoned prison of Alcatraz. It featured over 175 portraits of political activists and prisoners of conscience, such as Edward Snowden and Nelson Mandela.

During the 2015 Berlinale film festival, Ai Weiwei directed a movie which depicts his long-distance relationship with his six-year-old son, Ai Lao, who lives with his mother in Berlin. He delivered his instructions for the short film using satellites and via Skype, a logistical tour de force.

Ai Weiwei was allowed to hold a solo exhibition in Beijing in June 2015: This was seen as a sign that the government was easing on his case. Although he avoided direct political works in the show, the authorities pushed back its opening date by a week, as they did not want it to be accessible to the public before June 4 — the anniversary of the 1989 Tiananmen Square Massacre.

This is part of another famous work which counts millions of pieces. These sunflower seeds are deceptively realistic, yet they were all handcrafted in porcelain by hundreds of artisans. The installation comments on the current "Made in China" economy and also refers to Mao Zedong’s brutal Cultural Revolution (1966—76), where sunflowers were typically used in propaganda images.

There are different versions of this installation, "Circle of Animals/Zodiac Heads," which features 12 animal heads reproducing the traditional Chinese zodiac once part of a fountain clock at the Old Summer Palace in Beijing. The sculptures were looted after French and British troops destroyed the imperial retreat in 1850. In June 2015, a bronze version of the work was sold for 3.4 million pounds.

In 2014, Ai Weiwei held a huge solo exhibition in Berlin, which he also managed without leaving China. These 6,000 wooden stools filling the atrium of the Martin-Gropius Bau museum, collected throughout the countryside of his Homeland, did make the trip. Wooden stools have been used for centuries in households, and the artist sees them as a symbol of the disappearing traditions of rural China.

Private car ownership is growing exponentially in China, while the bike fleet is declining. Cyclists are being blamed for causing accidents and congestion. This work is made of 150 bicycles and also commemorates Yang Jia, a Beijing resident arrested for riding an unlicensed bicycle. During his detention he was assaulted and accused of murdering six police officers, leading him to a death sentence.

Ai Weiwei constantly posts pictures of himself on the Internet, such as this one. Air pollution is a major source of protest in China. Social media has become an integral part of the artist's work, allowing him to reach a very wide audience and establish his reputation as a dissident — inspiring many others. He was the recipient of Amnesty International's 2015 Ambassador of Conscience Award.