Naruhito’s father, the 91-year-old former Emperor Akihito, cared especially about Okinawa because of its difficult history, setting an example for his son.

The emperor and his wife, Empress Masako, asked their 23-year-old daughter, Princess Aiko, to accompany them on Wednesday’s trip in an apparent effort to convey their attention for history on the next generation. It is Aiko’s first visit to Okinawa.

The three first headed to the island’s last battlefield of Itoman and laid white flowers before an ossuary at the National War Dead Peace Mausoleum, where the remains of most of the victims are placed.

The Battle of Okinawa began on April 1, 1945 when the U.S. troops, in their push for mainland Japan, landed on the island. It lasted until late June, killing more than 200,000 people. Nearly half of them were civilian residents of Okinawa, including students and victims of mass suicides ordered by the Japanese military, which waged the war in the name of Naruhito’s grandfather, late Emperor Hirohito.

On June 23, the island will mark the 80th anniversary of the end of the Battle of Okinawa, which led to heavy American troop presence on the island, even after the nearly 30 years of U.S. occupation ended in 1972.

Naruhito, in his birthday remarks in February, stressed the importance of telling the tragedy of World War II to younger generations, pledging to contribute to efforts to promote the understanding of history and the determination for peace.

The imperial family later on Wednesday visited the Cornerstone of Peace memorial, which has the engraved names of about a quarter million war dead on the Mabuni Hill where the battle ended. They also visited a permanent war exhibit at the Okinawa Prefectural Peace Memorial Museum and met with the survivors and families of those bereaved in the battle.

Wednesday’s visit was Naruhito’s seventh visit to Okinawa. He last visited in 2022 to mark the 50th anniversary of Okinawa’s reversion to Japan.