since he had certainly four sons, but it is not in my power to inform the Reader who was his wife.

But I can --

He married Mary Bohun in 1380, who bore him seven children before her death in 1394.

In 1402, Henry remarried, taking as his bride Joan of Navarre, of whom it was rumored practiced necromancy -- talking to the dead, ie, a spiritualist/psychic -- was highly unpopular - she was, in fact, convicted of witchcraft in 1419.