Augustus Mirkdale was husband to Isabella Kalirion.
Appointed Deputy Director of Finance under the Directorate of Allocations & Appropriations of the State of Modan on 24.VII.1663.
As part of the Modanese Migration, granted asylum, nationality and residency in the Imperial State of Constancia on 21.IV.1668.
Served as Minister for Molivadia of the Imperial Constancian Government and Lord President of the Council of Molivadia from 1671 until his appointment as Vicegerent of of the Principality of Arboria in 1676.
By Decree of the Council of Arboria bearing date at the Court at Cape Isabella, Transegale on the 17th day of Dankember in the year 1688:
- they were both recognized under Arborian and Natopian law as Princess Esmeralda's stepfathers (this fact already recognized under Imperial Shirerithian law by Imperial Proclamation of the Kaiser of Shireroth bearing date 19.VI.1658 at Shirekeep 
- they were both granted the style of His Imperial Highness, but not the rank of prince, with precedence (in Arboria) immediately after Princess Esmeralda's children
- Augustus Mirkdale was erected, appointed and created and raised to the state degree style dignity title and honour of Duke of Cape Isabella, in the peerage of the Principality of Arboria of the Bovic Empire of the Natopian Nation, unto him and the heirs of his body lawfully begotten and to be begotten, with preference to the male heirs, with the clarification that these titles remain even in the event of their remarriage, and their spouses are entitled to the style His Highness or Her Highness, as applicable, and that their primary heirs are entitled to the style "The Most Honorable", their other heirs are entitled to the style, "The Very Honorable", and that dignities do not descend to an adopted heir or heiress
- Further clarification that that these dignities are limited to titles and do not include any territorial or land grants
- An award of a monthly pension of 50,000 natopos from the Treasury of the Principality henceforth until the end of their natural lives
- No pension shall accrue to their heirs or heiresses on their deaths
17.XIV.1688: His Imperial Highness The Duke of Cape Isabella, Knight of the Holy Lakes