Genetics, molar pregnancies and medieval ideas of monstrous births: the lump of flesh in The King of Tars.

The medieval English romance The King of Tars gives an account of a birth of a lump of flesh. This has been considered as fantastic and monstrous in past literature, the horrific union of a Christian and Saracen. However, while the text certainly speaks to miscegenation, we propose that this lump of flesh is actually a hydatidiform mole. We trace the hydatidiform mole from antiquity, surrounding it with contextual medieval examples, from theology, history and medicine, that also describe abnormal births as 'lumps of flesh'. By discussing medieval ideas of monsters as a warning sign, we interpret the lump of flesh in terms of abnormal births, seed transmission, parental contribution and sin. Ideas of warning, blame and intervention present themselves as a response to moles both in medieval texts as well as in modern reactions to hydatidiform moles. We explore the epigenetics of hydatidiform moles and relate them to the medieval text. In The King of Tars, the fault for the lump of flesh could reside with either parent; we find that this is also the case in the genetic formation of the hydatidiform mole; we also argue that the epigenetics supports medieval theories of seed transmission.