The Holy Empire of Amestris-Britannia is a massive, safe nation, ruled by Aoki vi Britannia - 宇宙の錬金術師 with an even hand, and renowned for its infamous sell-swords, daily referendums, and stringent health and safety legislation. The hard-working, democratic population of 2.922 billion Amestris-Britannians have some civil rights, but not too many, enjoy the freedom to spend their money however they like, to a point, and take part in free and open elections, although not too often.

The large government juggles the competing demands of Education, Industry, and Healthcare. It meets to discuss matters of state in the capital city of Amestris. Citizens pay a flat income tax of 53.4%.

The all-consuming Amestris-Britannian economy, worth 240 trillion Sekkis a year, is broadly diversified and led by the Information Technology industry, with significant contributions from Book Publishing, Basket Weaving, and Uranium Mining. Average income is 82,189 Sekkis, with the richest citizens earning 8.4 times as much as the poorest.

The government has declined to declare any particular religion as its 'official' one, families waiting for delayed pipe installations hope daily for rain, police officers often head to work wearing onesies and fluffy pink bunny-slippers, and snap elections are called over every minor impasse. Crime is totally unknown, thanks to a capable police force and progressive social policies in education and welfare. Amestris-Britannia's national animal is the Rat, which frolics freely in the nation's many lush forests, and its national religion is Freedom of worship.

Amestris-Britannia is ranked 29,045^th in the world and 1,389^th in The North Pacific for Most Efficient Economies, scoring 96.2 on the Krugman-Greenspan Business Outlook Index.