Relations with European settlers soured during the 1820s as settler encroachment increased and lethal violence against aboriginal clans was permitted by lax colonial policy. Seasonal passage through the midlands was hindered by opportunistic attacks from stockmen, such as the 'outrages' recorded against women of the Leterremairrener clan at Patersons Plains, north of Evandale, and also from larger scale organised assault by settlers, constabulary and military; which led to massacres at Norfolk Plains in the west and Campbelltown in the south. The aboriginal clans were severely depleted during this time but actively began a campaign of guerrilla attacks on settlers in the Midlands region that became known as the Black War.