  The bottomonium spectrum is the perfect testing ground for the confining
potential and unitarisation effects. The bottom quark is about three times
heavier than the charm quark, so that $b\bar{b}$ systems probe primarily the
short-range part of that potential. Also, the much smaller colour-hyperfine
interaction in the $B$ mesons make the $B\bar{B}$ threshold lie significantly
higher than the $D\bar{D}$ threshold in charmonium, on a relative scale of
course. A further complicating circumstance is that none of the experimentally
observed vector $b\bar{b}$ mesons has been positively identified as a
$^{3\!}D_1$ state, contrary to the situation in charmonium. This makes definite
conclusions about level splittings very problematic. Finally, there are
compelling indications that the $\Upsilon(10580)$ is not the $\Upsilon(4S)$
state, as is generally assumed. Here we review an analysis of experimental
bottomonium data which show indications of the two lowest and so far unlisted
$^{3\!}D_1$ states below the $B\bar{B}$ threshold. Next an empirical modelling
of vector $b\bar{b}$ resonances above the open-bottom threshold is revisited,
based on the Resonance-Spectrum-Expansion production formalism applied to other
experimental data. A recent effective-Lagrangian study supporting our
non-resonant assignment of the $\Upsilon(10580)$ is briefly discussed as well.
