Kammala jumla mai zuwa: Tarihin Niemirow mai yiwuwa ya koma karni na 11, lokacin da wani Slavic gord ya wanzu a nan. Binciken archaeological ya tabbatar da cewa mazaunan Mazovian da Ruthenian sun zauna a nan. Bayanan farko da aka rubuta game da ƙauyen ya fito ne daga 1495; a wancan lokacin, an kira shi Niwice. A cikin 1548, Sarki Zygmunt Agusta ya ba da ƙauyen ga wani mutum mai daraja Stanislaw Niemira (Gozdawa coat of arms), wanda jikansa, Castellan na Podlasie Stanislaw Niemira, ya canza sunan ƙauyen zuwa Niemirow kuma ya ba da takardar izinin gari. A cikin 1620, an gina kasuwar kasuwa tare da cocin Ikklisiya, kuma an fara kiran Niemirow a matsayin gari a cikin takardu daga 1631.
Harin Sweden da Transilvanian na Poland (1655-1660) ya sami mummunan sakamako ga garin, kamar yadda aka lalata shi gaba ɗaya, kuma a cikin 1662 yawanta ya kai 88 kawai.