Defterler

Defterler is the Turkish plural form of defter, a word meaning notebook, ledger, or register. In modern Turkish, a defter is a book used for writing notes or keeping records, and defterler refers to multiple such books or ledgers.

Historically, defterler were official registers in the Ottoman Empire, central to taxation and administration. They were used to record populations, households, land holdings, tax obligations, and military service. Among the most important were tahrir defterleri, census or tax registers prepared to determine tax assessments, and timar defterleri, records of land tenure and revenue arrangements. Other specialized defters documented customs, inventory, or state finances.

Because defterler preserve structured data, they are valuable primary sources for historians studying the Ottoman world. They illuminate demographic patterns, economic conditions, property rights, and administrative practices across regions and centuries.

Today, the word defter is widely used in Turkish to denote notebooks and accounting books in everyday life, education, and business. Defterler range from simple school notebooks to formal ledgers used in offices and households.