W. H. Johnson, a civil servant with the Survey of India proposed the "Johnson Line" in 1865, which put Aksai Chin in Jammu and Kashmir. This was the time of the Dungan revolt, when China did not control Xinjiang, so this line was never presented to the Chinese. Johnson presented this line to the Maharaja of Jammu and Kashmir, who then claimed the 18,000 square kilometres contained within his territory and by some accounts he claimed territory further north as far as the Sanju Pass in the Kun Lun Mountains. The Maharajah of Jammu and Kashmir constructed a fort at Shahidulla (modern-day Xaidulla), and had troops stationed there for some years to protect caravans. Eventually, most sources placed Shahidulla and the upper Karakash River firmly within the territory of Xinjiang (see accompanying map). According to Francis Younghusband, who explored the region in the late 1880s, there was only an abandoned fort and not one inhabited house at Shahidulla when he was there – it was just a convenient staging post and a convenient headquarters for the nomadic Kirghiz. The abandoned fort had apparently been built a few years earlier by the Dogras. In 1878 the Chinese had reconquered Xinjiang, and by 1890 they already had Shahidulla before the issue was decided. By 1892, China had erected boundary markers at Karakoram Pass.