On 9 June 1900, Claude MacDonald, the British Minister in Peking (Beijing), sent a telegram to the coast asking for reinforcements to the legations guards. Sensing the urgency of MacDonald's plight, Vice-Admiral Edward Seymour, the ranking officer in the gathered international presence off Taku, decided that further reinforcements should be sent immediately. He set off towards the capital on the next day in a convoy of 5 trains containing repair materials and a little over 2,000 seamen and marines of 8 nationalities. After meeting increasing resistance, initially from Boxers and later from Imperial troops as well, he was forced to abandon the trains and retreat, eventually limping into Tientsin (Tianjin) on 26 June. His losses amounted to 62 killed and 232 wounded.
This much is pretty clear form the historical record. Much else is wrapped in nationalistic/jingoistic colours on both sides.
Was it a calculated gamble or was it quixotic stupidity?
Was it a glorious failure or it was a great humiliation?
Was a lucky escape or it was a masterful retreat in the face of the enemy?
As is so often the case, it was probably all of these.
Calculated or Quixotic?
Due to rising concerns about Boxer violence, the Qin government had acceded to the International Powers sending guards to legation guards at the end of May, so Seymour must have calculated that they wouldn't get in the way of a wave of reinforcements. Whilst it would normally have taken just a few hours to travel the 80 miles to Peking, it was anticipated that some repairs would have to be made to the tracks - Boxers were known to have been causing damage - but it was still expected that the convoy would reach the capital the next day. They were not at war with China; they only had issues with the Boxer rebels. They were going to reinforce the legation guard in Peking; they weren't expecting to fight their way through more than few poorly-armed peasants. On that level, and without the benefit of hindsight, it doesn't seem to have been an unreasonable plan. Also, the expectation of an easy journey explains the oft-repeated jibe about officers paying more attention to the packing of their dress uniforms than of weapons and ammunition.
I think it should be recalled that Seymour had been a Midshipman in 1857 when the massacre at Cawnpore had caused such shockwaves. He would have served alongside naval officers who played their part in the suppression of the Indian Mutiny, and the tradition of the service of the Naval Brigades of the Shannon and the Pearl would have been strong in the fleet(1). I don't see how he could have failed to act to support the legations if it was at all in his power to do so. To remain inactive would have been unthinkable to an officer in his position. Whether he should have abandoned his squadron and put himself at the head of the expedition is another issue entirely, but as a quasi-diplomatic mission perhaps it made sense. Presumably he wasn't expecting to be at war with China within the week. Seymour was a relatively experienced China hand, and had earlier been keen not to exacerbate the situation by landing too many troops despite suggestions from Peking. He wasn't some gung-ho imperial warrior. You do wonder what would have happened if he had stayed with the fleet at Taku. Would the ultimatum to take the Taku forts ever have been made?
Glorious or humiliating?
It was humiliating, if only because the Chinese saw it as such. Seeing the westerners off was certainly a shot in the arm for the conservative faction. Whether it was the same for the Boxers involved may be more of a moot point, as they were often at the forefront of the initial attacks and suffered accordingly. Less and less is heard of Boxers activity from here on, and I do wonder if the realisation that none of them were invulnerable to missiles affected their elan.
However the fact remains that Seymour's expedition was able to wander around for two weeks, the second of which when they were officially at war with China. During that time they beat off attacks from Boxers and from much larger regular forces armed with modern weapons, including artillery that far outranged their own, and repeatedly fought through villages, roadblocks and even captured the largest arsenal in the area (even if they had no idea what it was at the time). They were rarely out of contact with the enemy, whether to their front, flanks or rear. They suffered heavy casualties, but they did pull through. Under the circumstances, mere survival was pretty glorious.
Lucky or Masterful?
OK, here's where I am in several minds.
I cannot see how a bunch of 2,000 matelots should have survived in the field, and indeed be free to manoeuvre at will, against 5,000-10,000 regular troops and many thousands of partisans who had them outflanked and surrounded. They were on foot; they were lost; they were transporting 200+ wounded. And remember that over 75% of them were sailors with little more infantry training than rifle drill. Clearly they fought hard and long, no doubt with the British Marines and the USMC playing a key part with their superior training and experience(2). But "Lucky" seems as unlikely as "Masterful" is just plain wrong.
Were they being shepherded back to Tientsin? That might fit with the Chinese way of war, where defeating an enemy without fighting him was the acme of good generalship. Western observers made much of comical drills that the saw being performed by Chinese troops, but there are other hints that these were drills designed to unbalance and surround rebels and unruly peasants without necessarily killing them. Remember, the Chinese had relatively little experience of war with another state, but centuries of putting down internal unrest. They followed the precepts of Sun Tzu (Sunzi), not of von Clausewitz, so we should not expect to see "absolute war" being pursued. By any measure you care to mention, the Seymour expedition had been defeated, so was it perhaps enough to see it limp homewards as it was no longer a threat?
As seductive as that idea is, it does not explain the attacks at Langfang, which were pressed home with some aggression and many casualties. Nor the heavy attacks against the Hsiku (Shiki) arsenal after it had been captured. I can only imagine that there was tension between the Boxers, Dong Fuxiang's Kansu Braves and the Tenacious Army of Nieh Shih-ch'eng (Nie Shicheng), meaning that command and plans were divided.
Ignoring the benefit of hindsight, I think it the decision to send the expedition on the short journey to the capital was unarguable, and not overly-fraught with risk. It fell apart because the boxer action was more widespread and destructive than at first thought - I suspect because the government forces had been heavily censured for there anti-boxer activities, and so went into huddle mode. But the expedition only fell apart when a state of war was created by the attack on the Taku forts, bringing in the active opposition of regular forces. From that point retreat was inevitable, and to retreat was to admit to the defeat of the expedition. That the expedition was able to reach safety, carrying so many wounded with them, was little short of a miracle, but one which based on hard fighting and poor Chinese coordination.
(1) Incidentally it was Rear-Admiral Sir Michael Seymour, commander-in-chief of the East Indies and China Station in 1857 and Edward Seymour's uncle, who ordered these ships to sail for India to assist in the suppression of the Mutiny.
(2) I'd love to know how well the French Fusilier Marins were trained. I believe they were better trained that your average naval rating, as this was supposed to be their métier, but I suspect that their tactical drills were not up to the levels of the RMLI, USMC or even troupes de la marine.