Researchers have found that Homo heidelbergensis was only slightly taller than the Neanderthal (SINC / José Antonio Peñas) see Scientists Determine Height of Homo Heidelbergensis
Here Homo heidelbergensis may be ancestor to Neanderthal and
Cro-Magnon
(modern homo sapiens sapiens), and we also have Neanderthal DNA so there was interbreeding between them as well, complicating the picture.