During the Russian Civil War Seth had managed to buy a pair of ships that he used to secure more and more people for his plan to take the Stargate even if for a few minutes. The records from that time show that he murdered his hosts children due to the sadism that every Goa'uld has lurking within their demented brains. Yet besides that the Marquess of Lothian and the parasite that had taken control of him stayed in his property. By the time 1925 rolled around he felt that he had enough men equipped and trained with Goa'uld Staff Weapons and Zat'nik'tels that he felt that the storming of the Stargate would be a victory and he could finally escape Earth and return to his rightful place in the stars amongst his brothers and sisters.
On the 10th of February 1925, the Marquess of Lothian booked a group of trains down to Leicester and through there the Stargate. It passed no notice save for the amount of carriages booked by the Marquess. As the train pulled out of Lothian station the world only had a few hours left of peace and solitude.
When the train pulled into the Stargate station assault began. The plasma shots melted the windows and dealt with the guards close to the station. From there the Seth's forces charged towards the Stargate and the DHD. The guards defending the gate were completely surprised and had never fought against men using plasma weapons before. Though Seth's forces had little military training they made up for it with both numbers and the amount of plasma they poured into the air. The brainwashed cult managed to take control of the gate and DHD after a brief shoot-out though they paid a heavy price. Then Seth marched forwards to the DHD and began to dial. When he activated the gate he and the core members of his cult marched in without a second thought. Just before a truck containing forces from the Grenadier Division pulled into the plaza that held the Stargate.
The British forces were higher trained then the guards had been and were able to break the cultists quickly. Then a small group leapt through the Stargate just before it closed. When they arrived on the world that Seth had dialled to most of them were killed except for one. Lieutenant J.R.R Tolkien survived as the shot aimed at him knocked him out instead of killing him. By the time he regained consciousness Seth and his men were long gone and Tolkien had to work out how to return home. He had been to New Windsor several times and knew the combination to get both there and to Earth. But when he dialled the first six buttons on the DHD neither the symbol for Earth nor New Windsor was there. Then he noticed that in the place of the unique Earth and New Windsor symbols there was a symbol he had never seen before with nothing else to do he dialled the gate. The connection opened successfully, and he returned to Earth in a state of shock.
-Extract from Christopher Tolkien's book My Father: A man of war and peace
The worlds reaction to Seth's attack and the return of Tolkien was absolute shock that was similar to the initial discovery of the Stargate. The world had assumed that it only went to New Windsor and the revelation that it could go to other planets threw the entire balance of power out of the window. The international community entered a decisively pro-British stance. As the world began to negotiate on how many migrants they could send to the new planet. As the world assumed that it was unpopulated much like New Windsor and the United Kingdom of Great Britain and Ireland would claim it much as they did with New Windsor.
This was proved decisively wrong when the British sent a small force through the gate to scout the area around the gate. At the time, the world that we now know today as Ùr Albion was under the control of the Goa'uld Apophis. The world was a backwater with only a small Jaffa detachment protecting the crops that the world grew. The British scouting party managed to stumble across the Jaffa detachment executing an old man for seemingly no reason. As the British watched the Jaffa proceeded to take the customary nine-tenths of the harvest from the farmers for Apophis. As the Jaffa left heading towards the Stargate the British scouts withdrew into the forests.
The corpses of the force that had followed Seth had been dealt with but if the Jaffa gave more than a cursory examination they would realize that something else had been there. The British decided to track the Jaffa and possibly eliminate them if the opportunity arose. When they reached the Stargate, they saw the Jaffa dial yet another address that they had never seen before. Then the Jaffa sent the cart containing the harvest through the gate and prepared to leave. As the Jaffa marched off one of them noticed the glint from the British weapons. The Jaffa opened fire and the rest of the Jaffa joined him. The Staff Weapons inaccuracy and slow rate of fire allowed the British to defeat them with relatively low casualties. The greatest success of the Skirmish was that one of the Jaffa was injured enough for the British to capture him and drag him back to the United Kingdom.
When the British returned from Ùr Albion with the captive Jaffa the world entered a state of shock the idea that there was an interstellar empire that bore plasma weapons and viewed them as disposable enough to station several on a backwater planet was incomprehensible to the powers of the world. As the halls of power across the world turned into shouting matches between politicians over how to deal with the United Kingdom the captured Jaffa was being interrogated. The British found out quite a bit from the Jaffa his name Dur'nead, to whom he was loyal 'the one true god Apophis' and what the vague state of the galaxy was under the rule of several 'false gods and Apophis'.
The British government still under the 'Welsh Wizard' of Liberal Prime Minister David Lloyd-George took the signs that the Jaffa had opened fire first as a symbol that Apophis had declared war on them and that any actions taken towards Apophis was in self-defence. The Goa'uld war had begun the longest and bloodiest conflict in human history but it showed the unity of humanity and brought about a period of inter galactic peace and prosperity.
-Extract from Robert C. Cooper's book Blood among the Stars: The Goa'uld War.