Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
Whatever we take into view--whether their own power,
their allies, or the resources of their antagonists--in all points the
plan of the Macedonian appears as a feasible, that of the Epirot an
impracticable, enterprise; the former as the completion of a great
historical task, the latter as a remarkable blunder; the former as
the foundation of a new system of states and of a new phase of
civilization, the latter as a mere episode in history.
The work of
Alexander outlived him, although its creator met an untimely death;
Pyrrhus saw with his own eyes the wreck of all his plans, ere death
called him away. Both were by nature daring and great, but Pyrrhus
was only the foremost general, Alexander was eminently the most gifted
statesman, of his time; and, if it is insight into what is and what is
not possible that distinguishes the hero from the adventurer, Pyrrhus
must be numbered among the latter class, and may as little be placed
on a parallel with his greater kinsman as the Constable of Bourbon may
be put in comparison with Louis the Eleventh.