In the eighteenth and nineteenth centuries, the Russian Empire opened the grasslands of southern Ukraine to agricultural settlement. Transformation on the Southern Ukrainian Steppe documents the Tsarist Mennonite experience through the papers of Johann Cornies (1789–1848), an ambitious and energetic leader of the Mennonite colony of Molochnaia. The third and final volume of Cornies’s papers, this book examines the later years of his leadership among the Mennonite settlers in southern Ukraine. Covering the period from 1843 to 1848, it reveals Cornies’s efforts to navigate the complex relationships between the Mennonites, the Russian state, and neighbouring communities. Highlighting Cornies as an ambitious reformer and key intermediary with the imperial government, the book explores how he played a pivotal role in shaping Mennonite prosperity in the region. Through his correspondence, it offers a unique glimpse into the workings of the colonial state and the tensions between religious tradition and secular ambition within the Mennonite community. This volume provides a rich portrayal of Cornies’s leadership, the evolving Mennonite community, and the personal struggles of a man balancing reform with tradition. Transformation on the Southern Ukrainian Steppe is an essential resource for scholars of Mennonite history, Russian colonialism, and minority life in the nineteenth century.