Władysław I the Elbow-high of Kujawy, however, as he had two older half-brothers from Casimir’s second marriage to Constance of Wrocław: Leszek II the Black ("Leszek Czarny") and Ziemomysł. He was named after his uncle, his mother's brother Władysław, Duke of Opole. Already in contemporary sources he was nicknamed ""Łokietek"", a diminutive of the word "łokieć". It translates as "elbow" or "ell" – a medieval unit of measure similar to a cubit, as in "elbow-high". The origin of this nickname, as resulting from Władysław’s short stature, was explained only in the 15th century by historian Jan Dlugosz. In 1267, when Władysław the Elbow-high was
Ancient Greek units of measurement Ancient Greek units of measurement Ancient Greek units of measurement varied according to location and epoch. Systems of ancient weights and measures evolved as needs changed; Solon and other lawgivers also reformed them "en bloc". Some units of measurement were found to be convenient for trade within the Mediterranean region and these units became increasingly common to different city states. The calibration and use of measuring devices became more sophisticated. By about 500 BC, Athens had a central depository of official weights and measures, the "Tholos", where merchants were required to test their measuring devices against official standards. Some Greek