Emperor Akihito of Japan is set to abdicate in the coming years, the country's public broadcaster NHK announced on Wednesday. It's been almost 200 years since an abdication took place when Emperor Kokaku stepped down, so what will this mean for the modern nation?
According to Japan's Imperial House law, the emperor is succeeded by the nearest male relative. This would be Crown Prince Naruhito, the elder son of the emperor and his wife Empress Michiko.
Naruhito, 56, is married to Crown Princess Masako and the couple have one daughter together Princess Aiko, 14.
The emperor's elder son Crown Prince Naruhito will succeed his father
It is not yet known when the emperor will abdicate. Instead NHK announced that it would happen in the coming years and speculation points to the 82-year-old emperor's poor health as the reason.
While the abdication would be an unprecedented move in Japan, Naruhito will no doubt be more than prepared to step into his father's shoes and succeed to the Chrysanthemum Throne.
The crown prince temporarily took charge of the emperor's duties when Akihito underwent heart surgery in 2012. This was not the first time that the head of state was plagued by illness. As he approached his 70th birthday, Akihito underwent surgery for prostate cancer and in 2011 he was again admitted to hospital suffering from pneumonia and bronchitis.
Naruhito's younger brother Prince Fuhimito is second in line
As for the question of who would succeed Naruhito, it would be his younger brother Prince Fuhimito, 50, who is currently second in line.
In contrast, Naruhito and his wife Masako's daughter Princess Aiko is not eligible for the role, according to Imperial House law. When Aiko was born a lively debate was sparked in Japan about whether the law should be changed from that of agnatic primogeniture – whereby the closest male ancestors inherit the throne – to absolute primogeniture, whereby gender is not an issue.
Naruhito's daughter Princess Aiko is not eligible to succeed to the throne
This would mean that Aiko, who is an only child, would succeed her father ahead of a younger brother or male cousin.
In October 2005 a panel of experts submitted a report, in favour of absolute primogeniture. The Prime Minister at the time, Junichirō Koizumi, even pledged his support.
However the proposals to change the Imperial House law were dropped after Aiko's male cousin Prince Hisahito was born. Hisahito is now third in line to the throne after his uncle the crown prince and his own father Prince Fuhimito.