Charles Joseph La Trobe arrived in Melbourne in October 1839 as Port Phillip's first Superindendant and he relieved Captain William Lonsdale of his General Agent of Government duties. The people of Melbourne marked the occasion by giving William Lonsdale an Address and financial gifts, from the settlers, including the new Superintendent. They presented him with 325 pounds for an inscribed silver service. Lonsdale continued to act as Police Magistrate until appointed as Sub-Treasurer of the district on a salary of 400 pounds in April 1840. His relations with Latrobe and the new Governor, Sir George Gipps, were always good. When local government was introduced to Melbourne Captain William Lonsdale was appointed the interim acting mayor until elections were held. When La Trobe was appointed acting as Lieut-Governor of Van Dieman's Land Captain William Lonsdale was appointed Acting Superintendent during La Trobe's absence.