Vicars Jacob was formerly attached to the 44th Madras Native Infantry.
He immigrated to Australia where he commenced business as a merchant in George Street Sydney .
In 1823 an article in the Sydney Gazette gives the reason for his decision to settle in Australia:
'Vickers Frederick Jacob, son of Vickers Jacob of George Street died on 9th instant. He was the third child of the Jacobs to die within four years. All had died from fever due to teething. The loss of the two former children was ascribed to the influence of the Indian climate. Mr. Jacob had retired from the service of the East Indian Company and settled in New South Wales under the hope of being here spared a similar trial but this last infliction has shewn the deceitfulness of such hopes and the inefficiency of human precautions.'
He was granted land on the Hunter River named Knock Finn and Millers Forest. The location of his grants can be seen top left on the map below.
Vicars Jacob was resident in the Hunter region by1824. His name also appears alongside 192 other men who were first granted allotments of land in Newcastle.
He was involved in a dispute with the military at Newcastle in this year when Magistrate Captain Henry Gillman entered Jacob's property without permission and was sued by Jacob for misuse of a search warrant. 
Assigned Convict Servants
Vicars Jacob also had difficulties with his convict servants. He had twenty prisoners assigned to him in 1824 and complained of their poor attitude in a letter to the Sydney Gazette.
Aaron Price - Guildford 1824
John O'Brien - Earl Grey 1836
William Jones - Hive 1834
Timothy Potter - Lord Melville 1829
Thomas Thorn - Mangles 1833
David Tunmore - Lord Melville 1829
John Murphy - Countess of Harcourt 1822
Richard Crossley - Prince Regent 1824
Thomas Brennan - Captain Cook 1832
Samuel Herring - Lady Harewood 1832
James White - Captain Cook 1832
John Booth - Isabella 1832
John Fernhead - Henry 1823
John Scott - Guildford 1824
Thomas Mitchell - Indefatigable 1812
Catherine Bryan - Mary 1822
His assigned servant Patrick Riley absconded in 1825 after being sentenced to 50 lashes for losing sheep. Riley was soon joined by other convicts from Jacob's Estate as well as two more from the nearby estates of Dr. Moran and John McDonnell. They formed a bushranging gang that became known as 'Mr. Jacob's Irish Brigade. This gang terrorised settlers in the lower Hunter for months.
Vicars Jacob died of fever died in Calcutta in 1836 shortly before embarking for Hobart. His wife continued the journey with their four children and died soon after arriving in Hobart.