Klaus was born on Earth where she enlisted within the United States Army and became part of the Stargate Program when the mysterious alien object was uncovered. Whilst the initial expedition had uncovered the planet Abydos, it was later discovered that another Stargate was present on Earth. In addition, an alien corpse was discovered which prompted the formation of another expedition to uncover the second Stargate. This mission was to be led by Commander Alexandria Klaus where she was to be assisted by Doctor Joel Murphy. The alien artifact was tracked to a newly discovered piece of landmass that was later designed as the Island of Doom. Traveling by the aircraft carrier Stormguard, Alexandria and her men were about to disembark when the ship was attacked by a large Mutant squid which had been distorted by the second Stargate's energy. It was only Alexandria's attempts at fighting the creature did she prove herself a capable leader and thus defeated the beast. Once that was accomplished, she took the members of her expedition onto the island in order to continue their mission.
Once they were on land, they met their guide Mustata who helped take them through the jungle. During their travel, they discovered another Star-Warrior but this specimen was in fact alive and warned them to turn back or be destroyed, When peaceful contact was offered, the creature struck Alexandria Klaus leading to a firefight with the alien. However, its advanced technology and unique physiology meant it was impervious to conventional attacks. It was only the timely arrival of Joel Murphy's use of a prototype electro-gun which send conflicting energies into the Star-Warrior thus killing it. Whilst distraught over taking a life, Commander Klaus assured him of the necessity and they continued with their mission. Eventually, they uncovered the second Stargate and she sent Dr Murphy to examine it. Just as he was about to do so, a spear was thrown from the trees which Alexandria managed to gun down with her pistol before it could harm Joel. Whilst initially unaware of the pistol attack and angry with Klaus, Alexandria pointed Dr Murphy to the emerging figures from the trees. A tribe of primitive humans initially spoke their own language which Mustata could translate but the leader of the tribe revealed that they had learnt English. She called herself Regalia and her people were the Children of Ra that worshipped the god Ra as well as were protecters of the "sacred" Stargate.
Commander Alexandria Klaus attempted to negotiate with Regalia and highlighted that they would be deactivating the Stargate as it was a threat to the planet. When this became clear to Regalia and that the intruders would not deviate, she struck and knocked Klaus back. This led to a firefight between the Children of Ra and Alexandria's forces though Klaus attempted to stop her own men from attacking though they did not listen to her. As the fight continued, the second Stargate opened once more and allowed more Star-Warriors to the field. When Regalia went before them, they struck her and began butchering both expedition personnel as well as her own Children of Ra. It was only a sudden airstrike to the region did the aliens retreat. In order to escape destruction, Alexandria along with her expedition and the surviving members of the Children of Ra also left the region. (Stargate: "Doomsday World 1", "Doomsday World 2", "Doomsday World 3", "One Nation Under Ra")
- She features in the alternate continuity of Stargate that does not feature SG-1.