He had people who worked for him called serfs.
He was a landowner, and the serfs would have been his tenants, working his land and paying him rent. The would also have provided infantry when he was called to provide men-at-arms.
To answer your question, the taxes you pay on the money you earn (salary, income) is called income tax.
The state where you work and earn the income wants to collect some state income tax on the income that you earn in that state.
My sister just earn her mothly income.
Income earned from shares is called dividend income and shown in income statement as "Other income".
$3500 or more
2200000
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Return
the Medieval Knight did not earn money. In return for his services to the lord or king, the knight would be payed by gaining land.
'Being a knight' is not an occupation and does not produce an income.
income is what you can earn including your salary, other suport income like your rental income and some profit payment
Income statements show net income for a period of time (income minus expenses).