Task: Question Answering
Input (English): Passage: The area now called Yarralumla is part of two original land grants, which were granted to free settlers for the establishment of farms. In 1828 Henry Donnison, a Sydney merchant who had arrived with his wife and family on the brig Ellen on 29–30 July 1828, was granted an allotment on the western side of Stirling Ridge. A second grant was made to William Klensendorlffe (a German who had served in the British Navy and arrived free in the Colony in 1818), who had bought the land from John Stephen, on 7 March 1839. Donnison's land was named Yarralumla in a survey of the area conducted in 1834. Yarralumla was a name for the area used by the local people, apparently meaning "echo". An area to the west of what is now the suburb was the Yarrolumla parish.The prominent New South Wales parliamentarian Sir Terence Aubrey Murray (1810–1873) purchased Yarralumla in 1837. He lived there with his wife Mary Murray (née Gibbes, 1817–1858), the second daughter of the Collector of Customs for NSW, Colonel John George Nathaniel Gibbes (1787–1873), MLC. In 1859, Murray sold Yarralumla to his brother-in-law, Augustus Onslow Manby Gibbes (1828–1897). Later that same year, Augustus' parents came to live with him at Yarralumla homestead.
Augustus Gibbes improved the estate and acquired additional land by purchase and lease. However, In 1881, he sold Yarralumla for 40,000 pounds to Frederick Campbell, a descendant of Robert Campbell, in order to travel overseas. Frederick Campbell erected a new, three-storey, brick house on the site of the former Yarralumla homestead at the beginning of the 1890s. Campbell's house would later form the basis of what is now the Governor-General of Australia's official Canberra residence, known colloquially as "Yarralumla" or "Government House". Campbell also built a large wooden woolshed nearby in 1904. It remains standing to this day.In 1908, the Limestone Plains area, including Yarralumla, was selected as the site for the capital city of the newly established Commonwealth of Australia. Soon afterwards in 1913, the Commonwealth Government purchased the property. Tenant farmers were allowed to stay on the land on annual leases, some remaining until 1963 when the Molonglo River was dammed to form Lake Burley Griffin. 
Question: What was the last name of the person Klensendorlffe bought land from?
Output (English): Stephen.