The eight-day visit to Britain by Emperor Naruhito and Empress Masako from Saturday highlights some 150 years of exchanges between the Japanese imperial family and the British royal family.

Their first exchange occurred in 1869, when Prince Alfred, the second son of Britain's Queen Victoria, visited Japan during an ocean voyage and met with Emperor Mutsuhito, who is posthumously known as Emperor Meiji.

Prince Alfred had a positive impression of the Japanese side at the time, according to Naotaka Kimizuka, professor at Kanto Gakuin University and expert on the British royal family.