International audienceThree rounds of archaeological excavations were carried out between September 2007 and October 2009 in the so-called "Palace of Trajan", a large urban house of Bosra, in southern Syria. The architectural study of this house brings out some remarkable features such as a reception hall with three apses (triconchos), amongst other things. Excavations carried out on the trench of the foundation of a facade wall allow us to date its construction to a period between the end of the fifth century and the beginning of the sixth century AD. However, the most important object of our archaeological study was the private bath, which occupies a large part of the house. It appears that this bath was far too complex in its layout and ...