In terms of colonialism, pretty much strong centralized leadership and an effective modernization of their military which made them just too strong to be worth taking over when there were far easier picking to be had in Africa.
All quotations are from General History of Africa: Volume VII Africa under Colonial Domination 1880-1935 edited by A. Adu Boahen.
Africa was pretty easy pickings for Europeans. "Africa was marked by inter-state and intra-state conflict and rivalry...while Europe could focus her attention militarily almost exclusively on her imperial activities overseas without any distraction at home." (22)
Not only that but the African powers had a massive disadvantage in terms of technology.
"...the overwhelming military and technological superiority that Europe enjoyed over Africa. While Europe was using professional and well-drilled armies, very few African states had established standing armies and fewer still had professional armies." (22)
One of the most important factors was the Brussels Convention of 1890 when "the imperial powers agreed not to sell arms to Africans. This meant that most African armies were armed with their traditional weapons of bows, arrows, spears, etc. or completely outmoded, old and often unserviceable guns, mainly flint-locks or muzzle loading muskets, and had no heavy artillery or navel power power whatsoever." (22) This was during at time when repeating rifles and the Gatling and Maxim guns were being employed.
On to Ethiopia.
Melenik, King of the Shoa, was able to retain good relations with the Italians during the 1880s when they began colonizing. Melenik took control of "the rich regions of Arusi, Harar, Kulo, and Konta to the south and south-east, and Gurage and Wallaga to the south-west." In 1889, he signed the Wuchale treaty, which promised him the right to "import arms and ammunition through Italian territory." (123)
The treaty had a difference in translation that made Melenik and Ethiopia a protectorate, which was ratified by the European powers but not entirely agreed upon. However, "Melenik refused to accept this interpretation and after several years' delay- which he turned to advantage by importing large quantities of firearms, especially from France and Russia, and conquering several provinces, including Kaffa, Wolamo, Sidamo, Bale, and eastern and western Oromo." He denounced the treaty in February of 1893 and at that time was "in possession of 82,000 rifles and twenty-eight cannon." (125)
Fighting would break out between the Italians and Ethiopions in late 1894. "Early in January 1895 the Italians attacked Ras Mangasha in Tigrai and occupied much of that province. Menelik thereupon ordered the mobilization of his military on 17 September, and marched north with a large force which won significant victories at Amba Alagi on 7 December and Makalle at the end of the year. The Italians then fell back on Adowa, where, after a period of inaction, the final battle took place.
Menelik was in a relatively strong position. He had the support of the local population, whose patriotism had been intensified by the fact that the Italians had been expropriating Eritrean land for the settlement of their colonists. The inhabitants were therefore willing to show his troops good paths and report on enemy movements. The Italians, on the other hand, had to face the enmity of the local people, and had no accurate maps; they therefore moved in confusion in an almost unknown country. Menelik's army, moreover, was much larger. It was composed of over 100,000 men with modern rifles, besides others with antique firearms and spears, whereas the invaders had only about 17,000 men, of whom 10,596 were Italian and the rest Eritrean levies. The Italians had some superiority in cannon, but with fifty-six to Menelik's forty this was by no means decisive.
The outcome of the day's fighting at Adowa was a remarkable victory for Menelik, and a complete defeat for his enemies. During the battle, 261 Italian officers, 2918 Italian NCOs and men, and about 2000 askaris, or local troops, were killed...Total Italian casualities amounted to over 40% of the fighting force, which was almost completely routed and lost all its artillery, besides 11,000 rifles.
As a result of Menelik's victory, the Italians agreed on 26 October, to the Peace Treaty of Addis Ababa, which annulled the Treaty of Wachale and recognized the absolute independence of Ethiopia.
The Adowa campaign gave Menelik considerable international prestige. The French and British dispatched diplomatic missions to sign treaties with him, while other embassies arrived from the Sudanese Mahdists, the Sultan of the Ottoman Empire and the Tsar of Russia." (125)
quick edit re-edited: should be 1894.
Also, why didn't Italians send another larger army to fight on? Did public opinion turn against the war back home? Did the people in charge just decide that it wasn't worth it? Or was it the recognition of other European powers that pressured Italy into giving up?
When British forces faced setbacks against the Zulus at Isandlwana they didn't exactly back down after the defeat.
The origins of the dispute between Italy and Ethiopia in the 1890s stemmed from the Treaty of Wuchale in 1889. That treaty was written in Amharic and Italian, but crucially the two versions of the treaty contained different wording and different intent.
In the Amharic version, the treaty included language that amounted to (and I am paraphrasing) "the Emperor may at his discretion call upon Italy in the business of conducting diplomatic relations with third parties"
In the Italian version, the wording amounted to "Italy will conduct diplomatic relations with other powers on behalf of the Emperor".
The difference in the wording is that the Amharic version carries the connotation that Ethiopia retains full sovreignty in foreign affairs, and may optionally request Italian assistance. The Italian version implies that Ethiopia has become a protectorate of Italy, and ceded control of her foreign affairs to Italian control.
Menelik II rightly considered the discrepancy in wording to be an attempt to establish a protectorate through deceit, and demanded an abrogation of the treaty.
Once Ethiopian forces were victorious at Adwa, Menelik shrewdly refrained from any attempt at annexing Italian territory. Instead, he reiterated his demands that the Treaty of Wuchale be abrogated, and a new treaty that recognized Ethiopian sovereignty in foreign affairs be negotiated.
So, from the point of the Italian government, the campaign leading up to Adwa had been an embarrassing disaster, and there was little point in assembling another army and conducting a further expensive campaign when the Ethiopian emperor was willing to restore the situation to the Status Quo Ante.
It's also worth pointing out that the defeat at Adwa led to the collapse of the sitting Italian government (Crispi's). Adwa also wasn't the only defeat that Italy suffered in the process; they had a lot of lost skirmishes in the campaign as well, and unlike the situation in kwaZulu, Menelik still potentially had a large and well-equipped army plus a great deal of sympathy in Europe (something amaZulu did not have, especially after the killing of the Prince Imperial). Italy was in political chaos, but Menelik couldn't press his advantage without risking his own political chaos, so he played it up as restraint which further burnished his image as a civilized leader. Add to that the fact that the Italian colonial military was full of Eritreans who wouldn't mount another expedition, and you have victories in both the field and in PR for Menelik and Taytu. Ray Jonas goes into this political jockeying in his Battle of Adwa (2011).
Him being an Ethiopian Orthodox Christian might have helped in that. Do any sources suggest that? Like, Europeans saying, a black Christian ruler, who is not even recently converted but it goes back a really long time, is preferable to the "savages" ?
Was there any evidence supporting Menelik's assumption? From his quick reaction I would assume that people tried to play this kind of trick often.
Also, it's interesting to note how different one document in two different languages can mean vastly different things. Do you know of any other cases where this has happened? I would assume it would be fairly common between countries that are not familiar with each others languages.
The Treaty of Waitangi, signed in 1840 between the British Empire and the Chiefs of most of the tribes of New Zealand also had differences in the two different versions. In the English version, the Māori (native people of New Zealand) ceded sovereignty to the Crown, whereas the Māori version states that they ceded governance, and retained their right to autonomy over the lands that their tribe controlled. It also claimed in the English version that the Crown had exclusive rights to purchase Māori land, whereas the Māori interpreted it as first rights to purchase. This caused problems later on with the Crown essentially buying land for much less than it was worth, as it had exclusive rights to purchase, and then selling it off to settlers for a much higher price. This caused European power to grow significantly, and severely diminished the power of the native Māori.
To this day these differences cause problems for New Zealand over who owns land and resource rights, such as the foreshore and seabed.
There's an argument that Menelik knew about the issue very early, and prepared his response carefully--moving to repudiate only once his domestic support was secure and wouldn't melt from under him like it did for Tewodoros II in 1868. But his opinion, and that of foreign correspondents sympathtic to him, is on record and well known--and also not at all unprecedented. That, in part, explains the lag between Wuchale and the Adwa campaign. But the question of whether he really didn't know about the translation issue, or he knew and dismissed it, or he knew and had no choice but to sign the treaty at that moment lest the Italians back one of his domestic enemies, is one historians still debate. Have a look at Jonas, who talks about this; Menelik expected treachery and certainly had Europeans among his advisors, besides which Ras Makonnen (his usual envoy [edit: and father of future emperor Haile Selassie]) was no fool.
