allow the recruitment of a quasi-official British Auxiliary Legion under George de Lacy Evans, which went to Spain to fight for Queen Isabel II against the followers of Don Carlos, the pretender to the Spanish throne. The Atholl Highlanders, a private Scottish infantry regiment of the Duke of Atholl, was formed in 1839 purely for ceremonial purposes. It was granted official regimental status by Queen Victoria in 1845 and is the only remaining legal private army in Europe. Turkey and Azerbaijan have deployed Syrian mercenaries during the 2020 Nagorno-Karabakh war. Russia has deployed Wagner Group mercenaries in the 2022 Russian invasion of Ukraine. Additionally, Syrian mercenaries are being deployed by Russia, with expected numbers ranging from hundreds to up to 40,000 fighters ultimately expected to take part. East Asia Warring States Mercenaries were regularly used by the kingdoms of the Warring States period of China. Military advisers and generals trained through the works of Mozi and Sun Tzu would regularly offer their services to kings and dukes. After the Qin conquest of the Warring States, the Qin and later Han Empires would also employ mercenaries – ranging from nomadic horse archers in the Northern steppes or soldiers from the Yue kingdoms of the South. The 7th century Tang Dynasty was also prominent for its use of mercenaries, when they hired Tibetan and Uyghur soldiers against invasion from the Göktürks and other steppe civilizations. 15th to 18th centuries The Saika mercenary group of the Kii Province, Japan, played a significant role during the Siege of Ishiyama Hongan-ji that took place between August 1570 to August 1580. The Saikashuu were famed for the support of Ikkō Buddhist sect movements and greatly impeded the advance of Oda Nobunaga's forces. Ninja were peasant farmers who learned the art of war to combat the daimyōs samurai. They were hired out by many as mercenaries to perform capture, infiltration and retrieval, and, most famously, assassinations. Ninja possibly originated around the 14th century, but were not widely known or used till the 15th century and carried on being hired till the mid 18th century. In the 16th-17th centuries, the Spanish in the Philippines employed samurai mercenaries from Japan to help control the archipelago. Abroad the wreck of one Spanish galleon, the San Diego, that sunk in Filipino waters on 14 December 1600 were found numerous tsubas, the handguards of the katanas, the distinctive swords used by the