During my lifetime, Mars and Jupiter have come to near-simultaneous opposition only once, in 1980.  They will do so again in 2027, a near repeat of the circumstances in 1980, both events being in Leo.  Over a time span of hundreds of years, most of these events are in the Cancer-Leo-Virgo direction, which means that Jupiter is much brighter than Mars, with a rather wide separation.  However, in 2746, they both come to a very rare near-simultaneous opposition in Pisces, at which both are near their peak brightness and with approximately the same latitude south of the ecliptic.  This is my crude photo illustration of the event using images I obtained during the 2020 oppositions of Mars and Jupiter.  On this date, closest to Mars' opposition, Mars is magnitude -2.65, while Jupiter is even brighter at magnitude -2.95, and only 3°31' west of Mars.

Mars and Jupiter in relation to the ecliptic in 2746

Mars and Jupiter retrograde loops through Pisces in Sept-Nov 2746