The mid-19th century can be said as the period in pursuit of armoured battleships. The world's maritime powers built large warships and heavy cannons competitively. Recommended by Li Hongzhang, the Qing dynasty appointed Lee Fengbau as Chinese Minister to Britain so that he could purchase armoured battleships in Germany. At the same time, it also desptached the engineer Xu Jianyin who was supposed to help Lee Fengbau purchase the armoured battleships. Lee Fengbau's mission was carried on by his successor Xu Jingcheng. This study, focused on diaries of Chinese Ministers to Germany such as Lee Fengbau, Xu Jingcheng, and Xu Jianyin and surrounding people, analyzed how the armoured battleships, cruisers and torpedo boats had been purchased in Germany during the late Qing dynasty, and dealt with the building process of the Beiyang Fleet.
The existing research raised a question on the excessively negative assessment on Robert Hart and James Duncan Campbell who had been engaged in warship purchase in Britain during the late Qing dynasty and comparative positive one on Lee Fengbau and Xu Jingcheng, and asserted that there should have been appropriate balance based on historical facts. Though Lee Fengbau or Xu Jingcheng might have outstanding talents, they were not so able to sort out sensitive matters like technology transfer in an equal relationship with foreign companies. It was because Germany's Krupp Corporation and Vulcan shipyard completely protected information on military technology like the British military industry. In this process, Chinese diplomats showed limits by putting more stress on weapon purchase than securing of technology.