Recent surveys of genetic diversity among Black Rats (Rattus rattus Complex) suggest a complex evolutionary history involving ancient allopatric divergence of 4 or more regional populations in South to East Asia,and recent genetic admixture following human-mediated range expansions and translocations.Many important questions remain regarding the genetic identity of regional black rat populations,their appropriate taxonomic names,and the adaptive and behavioural capacities and disease associations of different pure and admixed lineages.We present three sets of results: 1) a greatly expanded survey of global mtDNA diversity; 2) a global survey of Y-chromosome sequence diversity; and 3) microsatellite DNA data for regions of key interest.The combined datasets support the earlier hypothesis of allopatric diversification; identify several new evolutionary lineages; clarify the geographic distributions of all lineages; suggest potential natural hybrid zones; identify new instances of translocation of several lineages; and shed light on the genetic outcome of inter-lineage interaction in several different contexts.We will explore the evolutionary,taxonomic and management implications of the findings,and suggest new directions for future research and international collaboration.