Mark	Era	Features	Generation typified by:
Mark VI	Just pre-TOS
Mark VII	TOS	The first highly reliable generation, featuring: long sustained warp capabilities deployment times in excess of three years mean-time-in-space marks in excess of 60% pinpoint accuracy phasers photon torpedos	Active construction between 2220 and 2270. Exploration, expansion, small skirmishes and short wars
Mark VIII	Movie	featuring: long sustained warp capabilities increased warp speeds deployment times in excess of three years mean-time-in-space marks in excess of 70% large production runs of reliable designs, such as Miranda upgrades of older ships	Active construction between 2260 and 2300. Exploration, expansion, consolidation, small skirmishes
Mark IX	Excelsior	featuring: long sustained warp capabilities deployment times in excess of four years Increased sensor capabilities mean-time-in-space marks in excess of 70% standardization of role-based nomenclature experiments with alternative propulsion large production runs of reliable designs, such as Excelsior	Active construction between 2280 and 2325. Exploration, consolidation, general peace, but with conflicts toward the end of the period
Mark X	Lost Generation	Mark X technology was a significant advance on Mark IX, but proved too costly, and was abandoned in favor of enhancement programs for older ships and a cheaper next-generation technology. Mark X featured: long sustained high-speed warp capabilities greatly enhanced computer capabilities high degree of automation warp-capable sub-components (saucers) data-link multi-ship networks	Limited construction 2325-2330. Little exploration, mostly consolidation, peace, and financial exigency.
Mark XI	Ambassador	Mark XI was a minor advance over Mark IX. Instead of concentrating on technology, Mark XI concentrated on "Ship features" such as size increase, strength, and durability featuring: long sustained high-speed warp capabilities greatly increased size greatly enhanced habitability strip phasers photon torpedo cluster launchers mean-time-in-space marks in excess of 90%	Active construction 2335-2360. Intense SLEP programs during same periods. Some Exploration, many small skirmishes, large war with Cardassia toward end of period.
Mark XII	Galaxy	The Mark XII generation featured a first-phase approach to revisiting Mark X technology, combined with a continuation of the size-growth trend started in Mark XI. Mark XII also featured the first examples of size dimorphism: that is, larger and smaller versions of the same general types of ships. These are referred to as "Senior trend" and "Junior trend" ships. Mark XII technology features: very long sustained high-speed warp capabilities continued increased size greatly enhanced habitability, including non-crew provisions multi-target strip phasers rapid-fire photon torpedo launchers experimentation with variable geometry nacelles experimentation with long-axis and wide-axis primary hull configurations long-duration dedicated warships mean-time-in-space marks around 80% The Mark XII generation also saw Starfleet use for the first time non-Starfleet designs and procurement, in order to increase fleet size without significantly impacting strategic production. This includes: mass-produced private venture designs such as Sabre and Steamrunner purchase of speculative designs such as Akira experimentation with non-traditional designs such as Defiant and Norway SLEP programs for older vessels	Active construction 2350-2370. Some programs curtailed. Exploration, consolidation, major conflicts with Borg, Cardassians
Mark XIII	Soveriegn	Mark XIII technology is the second phase of revisiting and re-thinking Mark X technology. Mark XII put int practice and reality some of the ship-features of Mark X, Mark XIII concentrated on the processing and capability features of Mark X. However, much progress on Mark XIII was delayed by the dominion wars. Mark XIII includes: continuation of dimorphism greatly enhanced internal processing and computer power greatly enhanced defensive technology, particularly armor exceptionally high sustained warp speeds preference for long-axis saucers experiments with multi-vector attack vessels	Active construction 2365-2380+. Some programs curtailed or delayed. Little exploration, intense conflict with Dominion, Cardassia, others.