Rubuta ci gaba don wannan sakin layi - Bayan Yakin Poland da Rasha, Ostrołęka ya zama ɗayan biranen da aka fi lalata su. Kodayake ya sha wahala sosai, Ostrołęka ya kasance birni na gundumar Płock. Tattalin arzikin Ostrołęka ya ragu sosai. Kusan dukan masu sana'a na birnin sun fatara. Kayan aikin Ostrołęka na amber ne kawai ake samarwa a duk Turai. Ostrołęka ya sami ramuwar gayya daga Baitulmalin Sarkin. Duk da haka, ya ɗauki lokaci mai tsawo kafin ya tashi daga faɗuwarsa. A cikin 1847 wani abin tunawa da ke tunawa da nasarar sojojin Rasha a yakin Ostrołęka
an tayar da shi a ranar 26 ga Mayu 1831. A lokacin tashin hankalin Janairu, ba a yi yaƙe-yaƙe a kusa da Ostrołęka ba, kamar yadda Sarkin ya sanya babban rukunin Rasha a cikin birni yana damuwa da wani tashin hankali na Kurp. A cikin 1864, bayan umarnin gwamnatin Rasha, Benedictines sun bar Ostrołęka kuma an sanya gine-ginen gidan sufi a ƙarƙashin ikon firist.