When Portugal acquiesced to British demands, it was considered as a breach of the Treaty of Windsor (1386) and seen as a national humiliation by republicans in Portugal, who denounced the government and the King as responsible for it. The government fell, and António de Serpa Pimentel was appointed prime minister. The British Ultimatum inspired the original lyrics of the Portuguese National Anthem, "A Portuguesa". It was considered by Portuguese historians and politicians at that time to be the most outrageous and infamous action of the UK against its oldest ally. The reason that Lord Salisbury and his diplomatically isolated British government used tactics that could have led to war has been plausibly argued as the result of fear of Portuguese occupation of Manicaland and the Shire Highlands, which would have forestalled British interests.