Population was obliged to support the church. The tax was called "bir" ("picked", "collected') and originally included only goods, mostly food. The tax was known as "popovski bir" or "duhovni bir" (priestly tax, or spiritual tax, respectively). In the 14th century, it was partially, and then fully, replaced with money. In the mid-14th century, during the reign of Emperor Dušan, it was recorded that Serbs pay "lukno žita ili 2 dinara" (one measure of grain or 2 dinars), while Albanians were paying half of that ("poluknica ili dinar"). It was a much lesser taxation, and easier to pay, than the "vlastelinski bir" or "vladaočev bir" (noblemen's tax and ruler's tax). The tax survived the Middle Ages. During the Ottoman occupation it reverted fully to being paid in food. It survived into the modern Serbian state after the liberation, being replaced with money again in the late 19th century. The verb "ubirati", from the old "bir", remained in modern Serbian language, still depicting the tax collecting ("ubirati porez").