Ireland’s great-uncle Mark was the youngest brother of his grandfather John Nicholson. Mark Nicholson (1818–89) was born at Clifton, near Bristol. His older brothers were John and William Alleyne, the latter of Nicholson River fame. Mark Nicholson is another member of the family to emigrate to Australia, sailing for Melbourne on the Duchess of Kent. He landed at Port Phillip in June 1840. According to the entry by R.M. Jukes in the Australian Dictionary of Biography:
he took up a cattle run near Mount Macedon with a relation, Dr Edmund Higgins, as partner. In 1845 Nicholson left it and took up Lake Wangoom as well as Cudgee and Mount Warrnambool with Craigieburn as an out-station. In that year he married his cousin Elizabeth Cobham…becoming connected with other prominent people in the formative years of the Port Phillip District. In 1848 Superintendent La Trobe asked Nicholson, Thomas Manifold and Henry Foster to become justices of the peace so that the new town of Warrnambool might have more influence in the Magistrates’ Court at Belfast (Port Fairy). As prominent churchmen, Nicholson and Foster were requested by Bishop Perry to conduct services in the township until Dr Beamish became the incumbent in 1850. In 1853 Nicholson was elected, unknown to himself, to represent Belfast and Warrnambool in the Victorian Legislative Council… He successfully moved for a survey of the ports of Belfast and Warrnambool. He was also responsible for the motion to provide funds in 1854 for a museum of natural history, now the National Museum of Victoria. He resigned in 1854 in order to return to England to educate his children.
Nicholson visited Victoria on business in 1859 and 1868, and in 1873 returned with his family to settle. In his 72nd year he died at his home, Waveney, near Warrnambool, on 27 October 1889. His generosity, charm and talent for friendship had won him a wide circle of friends.
Mark Nicholson had five sons and two daughters.