Other members of the imperial family perform ceremonial and social duties, but have no role in the affairs of government.

[3][4][5] The earliest historic written mentions of Japan were in Chinese records, where it was referred to as Wa (倭 later 和), which later evolved into the Japanese name of Wakoku (倭國).

While the main line of the dynasty does not have a name and is referred to as Kōshitsu (皇室, imperial house), there are agnatic cadet branches which split during the course of centuries who received their own family names in order to distinguish them from the main line.

Furthermore there are branches created from sons of the emperor who were excluded from the line of succession and demoted into the ranks of the court (kuge) or sword (buke) nobility.

Such families are the Minamoto (源 also known as Genji), Taira (平 also known as Heishi) and Abe (安倍), as well as through in-laws the Tachibana (橘) for example.

Out of these families further branches split through male descent who were also considered noble Japanese clans.

[10] In English, shinnō (親王) and ō (王) are both translated as "prince" as well as shinnōhi (親王妃), naishinnō (内親王), ōhi (王妃) and joō (女王) as "princess".

In 1921, due to the poor economic situation in Japan, 289,259.25 acres (117,059.07 ha) of crown lands (26%) were sold or transferred to the Japanese government and the private sector.

At the end of 1935, the Imperial Court owned 3,111,965 acres (1,259,368 ha) landed estates according to official government figures.

It comprised palace complexes, forest and farm lands and other residential and commercial properties.

[note 1][23][24] Emperor Shōwa's personal fortune was an additional hundreds of millions of yen (estimated over $6 billion as of 2017[update]).

It included numerous family heirlooms and furnishings, purebred livestock and investments in major Japanese firms, such as the Bank of Japan, other major Japanese banks, the Imperial Hotel and Nippon Yusen.

[23] After World War II, all of the 11 collateral branches of the Imperial Family were abolished under the Allied occupation of Japan, and the subsequent constitutional reforms imposed under Allied supervision forced those families to sell their assets to private or government owners.

The Tōgū Palace is located in the larger Akasaka Estate where numerous other Imperial Family members reside.

[29] Until 2003, facts about the Japanese Imperial Family's life and finances were kept secret behind the "Chrysanthemum Curtain."

Yohei Mori (former royal correspondent for the Mainichi Shimbun and assistant professor of journalism at Seijo University) revealed details about finances of the Imperial Family in his book based on 200 documents that were published with the public information law.

This includes a 24-piece traditional orchestra (gagaku) with 1,000 year-old instruments such as the koto and the shō, 30 gardeners, 25 chefs, 40 chauffeurs as well as 78 builders, plumbers and electricians.

The Emperor has four doctors on standby 24 hours a day, five men manage his wardrobe and 11 assist in Shinto rites.

The first of these specially prepared vehicles, Empress 1, serve as the official state car of the Emperor.

[31][32] Despite the imperial family's extravagant expenditures, there is a limitation with travel expenses since the Emperor's entourage pays a maximum of £110 a night, regardless of the actual cost of the hotel.

For example, Prince Tomohito of Mikasa, his wife and two daughters received £310,000 per year, but they are not well known by the Japanese public and have had few imperial duties.

The imperial system is considered a symbol of the country, it provides a sense of linkage, purpose, spiritual core, diplomatic role as ambassador and a source of tradition and stability.

A small percentage argue that the imperial system is out of date, not in synchrony with the contemporary times.

[36] Unless otherwise noted (as BC), years are in CE / AD  * Imperial Consort and Regent Empress Jingū is not traditionally listed.