Here we describe a new historical database on major floods (and associated weather systems) that occurred in a 1500km strip in coastal southeastern Australia during 1860-2012. Two types of weather systems are found to trigger all of the 253 major floods identified: East Coast Lows (ECLs) and “Tropical Interactions” (TIs). ECLs triggered more major floods (57%) than TIs (43%), but death tolls from freshwater flooding linked to TIs tend to be much higher. The influence of the El Niño-Southern Oscillation on floods, weather events and death tolls will be discussed. Some of the most extreme events identified occurred in the 19^th and early 20^th centuries. If such events were to occur nowadays they would have catastrophic impacts. It is therefore crucial that weather and flood information beyond experience obtained in the last few decades is factored in to planning.