The Lithuanian Metrica or the Metrica of the Grand Duchy of Lithuania (Latin: Acta Magni Ducatus Lithuaniae, Lithuanian: Lietuvos Metrika, Polish: Metryka Litewska, or Metryka Wielkiego Księstwa Litewskiego; Belarusian: Літоўская Метрыка, Ukrainian: Литовська метрика) is a collection of the 14–18th century legal documents of the Chancellery of the Grand Duchy of Lithuania (GDL). Maintained systematically since the 2nd half the 15th century, metrica consisted, initially and primarily, of the copies of the documents issued by the Grand Duke, Lithuanian Council of Lords, and Seimas.