Operation Holy Shroud
Operation Holy Shroud was a series of Inner Sphere wide covert attacks by agents of ComStar's ROM intelligence division against the Great Houses' attempt to preserve or rediscover technology lost during the First and Second Succession Wars.
As the Second Succession War began to draw to a close, the fighting had devastated many specialized technologies. It became increasingly hard to produce advanced items such as JumpShips and advanced computers, because the factories that produced them were rapidly being destroyed; thanks to cannibalizing existing equipment, the Great Houses were able to maintain their current war machines and slowly rediscover how to build them. 
However the newly invested Primus Raymond Karpov felt that even this was too much of a threat to the eventual dominance of ComStar over the Inner Sphere. To this end in 2838 he presented Organizational Edict 3056 to the First Circuit which called for an expansion of the Order's intelligence division ROM as well as increasing its scope from internal security to actively targeting and eliminating scientific and technical experts among the Inner Sphere Great Houses. 
After removing those who challenged this new step, including Karpov's long time friend and Precentor ROM, Michelle Dupreas, the ranks of ROM were replaced by his staunch supporters, and the newly agreeable ROM quickly drew up a list of over a hundred key researchers and scientists, and began planning new covert assassinations. 
ROM prevented scientists of the Federated Suns from making advances in the field of interplanetary communication so the Order could maintain monopoly control of Hyperpulse Generators. Operation Holy Shroud soon expanded to targeting laboratories and scientists working on a wide range of military and civilian technology. Further, under the egresses of Operation Holy Shroud, ROM agents attempted to quickly unearth as many supply and military caches left behind by the departed Star League Defense Force as possible so the Great Houses would not find them.
By the time Holy Shroud drew to a close in 2843, ROM had systematically eliminated over 300 of the best scientific minds in the Inner Sphere. As each House suspected that the seemingly accidental deaths and destruction affecting their efforts to recover and maintain advanced technology could only be intentional covert attacks, the skill of ROM's agents in covering their tracks and ComStar's professed neutrality ensured that each blamed the other instead of the Order.
For ComStar the operation was highly successful, with many technologies taken for granted less than two generations before all but disappeared outside of the halls of the Order. However, while it accelerated the decline of many technological fields, it also helped contribute to the need for the war-weary Successor States to abandon the Second Succession War so as to rebuild and attempt to recover what advanced technology they could. This renewed effort forced Karpov to take much more drastic measures, fanning preexisting conflicts which helped trigger the Third Succession War. 
The success of the Operation led later Primus Yin Takami to order Operation Holy Shroud II in 2979, however by this time the majority of the Great Houses had taken much more extensive efforts to successfully protect their scientific resources and the second Holy Shroud proved but a pale shadow of the first.
- ComStar, pp. 28-30 "The Consolidation Years - Karpov Ascendant - ComStar Strikes"
Field Manual: ComStar - pp 12