Santa was originally born around 1700 years ago as Nicholas of Myra (in modern day Turkey). Because of his exceptional compassion for children and the needy, and his willingness to fight against injustice (as witnessed by his brawl with Arius), Nicholas was named a saint, and was granted immortality by God so long as he continued in the Path of compassion and justice.
Nicholas spent the first several centuries covertly fighting injustice and doing good for poor children in the region of the Middle East. Every Christmas, in honor of Christ, he snuck into the houses of the impoverished and left gifts. But as time went on, Nicholas grew curious about the world God created. Under aliases and a long beard, he began to study what was once called "Natural Philosophy", and later "Empirical Science" in places such as the Great Library of Alexandria, Tang Dynasty China, Abbasid Baghdad, Mughal India, the University of Paris, and early modern Oxford.
By the early 1800s, with centuries of accumulated knowledge, Nicholas far surpassed the best technological minds the world had ever known. And his legendary sweet tooth led his waist size to surpass every pair of pants he ever owned. But with the gift of immortality, he didn't have to worry about cholesterol, so the more the merrier!
On Christmas Eve of 1812, Nicholas learned how to warp space and time, appearing to move at relativistic speeds (i.e. near the speed of light) relative to an outside observer, while moving at "normal" speed relative to himself. Within the next year, using the same technology, he also developed the ability to create pocket universes. This led to the intervention of alien "Time Lords" who were alerted to the change of technology on planet Earth. Nicholas was captured and taken to Cygnus 7, home of the headquarters of the "Sentient Alliance for Negating Temporal Aggression" (S.A.N.T.A. For short). Once the agents of SANTA interrogated Nicholas for several years, bribing him with milk and cookies, they determined that he was in fact a morally virtuous immortal, who was granted Divine abilities to fight evil and spread compassion throughout the universe.
Thus thoroughly vetted, Nicholas was trained and granted "agent" status with SANTA as the protector for the Sol star system, and in particular for the third planet, Earth. He was sent back with instructions to protect Earth from attack by malevolent aliens, and to make sure that the timeline was not tampered with. He was now a Time Lord with the designation SANTA agent Nicholas, which was a real mouthful, and was eventually shortened to Santa Claus.
He set up his base with a small portal to a pocket universe in the most inhospitable place on Earth: The North Pole. From his secret base, he protects the Earth and her Solar system from nefarious threats in space and time. His pocket universe home base is staffed by several hundred aliens from all around the galaxy who help monitor the solar system and timeline, and who fabricate the tools Santa Claus needs to protect us. Usually the home base on a planet would be mainly staffed by life forms from that planet. But since the Earth is still so technologically and socially backward, the Time Lords of SANTA thought it best to staff our base with aliens until we grow up. Only one other human has attained Time Lord status, and she is known as "Mrs. Claus". Her identity is to be kept a secret at all costs, but legend has it she bakes the best cookie this side of galaxy center.
Starting soon after the establishment of his base in the mid-1800's, Santa Claus also began to enlarge his yearly gift giving to children at Christmas time. First the aliens living and working with Nicholas joined in by fabricating the best toys at the top technological level for Earth society in any given year. Second, these toys are housed in a pocket universe that holds a vast robotically controlled warehouse that is able to retrieve any toy in seconds. Third, he developed satchels that housed a portal to that pocket universe, which could easily be carried over the shoulder. Fourth, he created transdimensional time sleds which make use of 5th and 6th dimensional space, so they can appear "inside" the houses of families without having to go through walls or doors.
Thus equipped, Santa Claus, along with his alien helpers which he calls his "elves", drop off presents to every child in the world who is on the "nice" list (although Santa Claus almost always caves in and gives gifts to the "naughty" kids too). Because of the time warping effect of transdimensional travel, it appears from Earth perspective that it takes them about 1.8 seconds to deliver presents to every child on Earth. From the perspective of Santa and his elves, it takes about 6 months. Yet since he is immortal, and most advanced alien species live for centuries, the time spent making and delivering toys doesn't matter compared to the joy it creates.
This, of course, explains why we don't have records of the worldwide phenomenon of Santa delivering toys to children all over the world until stories started coming out in the mid-1800s. Santa's gift storage and delivery technology did not exist until then! It also explains why the North Pole base has never been found, and will never be found, until human technology leaps forward. From an Earth perspective, his "base" is just one well-cloaked transdimensional portal that does not appear visible in three dimensions. It emits tachyon particles and slightly warps gravity, but we won't be able to detect that for decades if not centuries.
But we do need to clear up a couple of misconceptions: First, Santa himself does not actually hand-deliver every package. He divides Earth up into several hundred zones for himself and all of his alien elves. But since most Earth humans would be very disturbed by the idea of aliens visiting their house, they happily allow Santa to take all of the credit. Perhaps some day when Earth society and technology has evolved, the full truth can come out. Because the truth is out there!
Second: We also need to deal with the truth behind the reindeer. These, of course, are not the furry mammals that live in the tundra of the northern hemisphere. Everybody knows they cannot fly, and they hate pulling sleighs! REINDEER is simply another acronym for "Radiant Energy INduction for Dimensional Expansion and Extraction Robots". Basically, they are all purpose robots which supply the power which is necessary for the warp drive housed in the sleighs. The appearance of looking like a deer comes from the four legs which house ion thrusters. The "red nose" is the quantum fusion engine housed in the forward half of the robot. And because the fusion engine throws off lethal amounts of radiation, it has to be tethered to the sled by carbon filament cables several hundred meters long, to give space for the buffering force fields to contain the radiation. But don't worry: Since the REINDEER operate outside of the three dimensions of Earth space, none of the radiation ever makes it inside anyone's home. And because most people would be alarmed that radioactive four legged robots are pulling the warp sleighs, Santa is more than happy to have folks believe the story about the reindeer.
Well, I guess that is all we really need to know about Santa Claus, and how he delivers gifts every year. You may now be wondering "Well what does Santa do the other 364 days, 23 hours, 59 minutes, and 58.2 seconds of the year?" Well, he is fighting to keep our timeline safe from enemies! But that is another story for another time...
Thanks for reading my incoherent babble. May strength and compassion and wisdom fill your life. // Nate.