The agricultural domain of Bielenfeld spans the mighty Donza River, and is organized into "plantations". Each Xyz plantation is ruled by a noble von Xyz family, called Squires. Bielenfeld was the blueprint for Shin Makoku - Shin Makoku means "new demon kingdom". Bielenfeld was the old one.
Tarkenburg is by far the biggest plantation, taking up the west bank of the Donza. The von Bielenfelds have the east bank plus some, but split into 7 plantations.
Though the term "plantation" is agricultural, some plantations include major towns and industry. Tarkenburg sports manufacturing, major shipyards, and river port as well.
Tarkenburg excels in agricultural research, especially potatoes. Aldrich von Bielenfeld's plantation (AvB) is a major potato rival. Much to Aldrich's annoyance, not only do Tarkenburg Purples taste better, but Tarkenburg's Bielenfeld Blue potatoes are bluer than Aldrich's.
Bielenfeld is an aristocratic democracy. Squires have votes in the domain-wide conferences, in proportion to their plantation population. 'The Biel' collectively have more votes, but the Tark is the single largest vote block. The Tark is monolithic to outsiders, a very tight clan. Whereas 'the Biel' (only called that in comparison to the Tark) is actually two families of rugged individualists.
People frequently joke about western Bielenfeld becoming the domain of Tarkenburg. The Tark and the Biel don't laugh at that joke.