William was born 1757 Bradford, Wiltshire, England. He arrived in NSW as member of Marines 8th Company, been a ship marine of HM Supply in 1788. William was discharged on 20 May 1789 from HM Supply to HQ Port Jackson. William arrived on Norfolk Island aboard HM Supply in Mar 1790 a Marine as part of the Garrison.
On Norfolk Island he formed a relationship with Tamasin Allen, Convict, Lady Penrhyn 1788 who arrived on Norfolk Island aboard HMS Sirius in Mar 1790. In Mar 1791 William requested to remain on Norfolk Island as a Settler.  William left Norfolk Island and discharged from the marines upon his arrival in Sydney in Oct 1791. After returning to Sydney, William obtained permission to become at Settler on Norfolk Island, returning aboard the Atlantic in Oct 1791. William and Tamasin were one of the many couples married by Reverend Richard Johnson, in Nov 1791 on Norfolk Island.
Upon his return to Norfolk Island William Syms was granted 60 acres of land, being Lot 64, on 24 Nov 1791. This land was sold to ex-convict Andrew Goodwin on 19 Feb 1796. In about 1800 Cornelius acquired the 60 acres of land on Norfolk Island from Andrew Goodwin, This land today is located at the rear of the Governors Lodge, east of Taylor Road on Norfolk Island, along to Middle Gate Road, at the rear of the Ocean Breeze Apartments.
In 1793 William was working as a Constable at Cascade on Norfolk Island. Tasmin received rations until 1794 on Norfolk Island. In June 1794 Tasmin was recorded free, married with one child (William), off stores supported by William Simms.
William joined the NSW Corps on Norfolk Island on 22 Aug 1800.
1801 Temison Allen: Abode: Sydney, off stores.
1806 Jamison Allen: Concubine with William Symms, Soldier with one natural male child.
William was transferred to the 73rd Regiment in Apr 1810 with the rank of private.
William and Tamasin along with their two sons went to Ceylon in 1814 and then travel to England. William at the age of 59 years was discharged in Jul 1816 after service on the 19th Dragoons (Light), 76th Foot Regiment and 73rd Foot Regiment.
In 1816 William and Tasmania petitioned to return to NSW (it seems that their two children may had already returned) . The date they returned to NSW is unknown.
1822 Sampson Allen: Abode: Sydney.
A circumstance occurred only the other day in Pitt Street, when an infirm old woman (Mrs. Simms) was attacked by a large mastiff; and it was, with great difficulty, the poor aged female escaped with nearly the loss of her right hand. As for the carmen, (cabman) they appear absolutely to be beyond the reach of the law, and seem to bid defiance to the arm of justice.
1823 Jamieson Simms: Abode: Benevolent Asylum, Sydney.
Tamisson Simms died 10 November 1825 Sydney Benevolent Asylum, age 76 years, buried 11 November 1825 Devonshire Street Cemetery Sydney.
Children of William Simms and Tamasin Allen:
- William ALLEN, born 12 Aug 1792 Norfolk Island. William received half rations in 1793 and 1794. Enlisted into the NSW Corps and transferred to the 73rd Regiment in 1810. William Simms went to Ceylon in 1814 and said to have returned to NSW. After service with the 73rd Foot Regiment and 83rd Foot Regiment. He was discharged at the age of 37 years in 1829 in England.
- John ALLEN, born 1796 Norfolk Island. John Simms enlisted into the NSW Corps and transferred to the 73rd Regiment in 1810 and went to Ceylon in 1814 and said to have returned to NSW.
 Return of the Non-commissioned Officers, Drummers, and Privates of the Detachment of Marines serving at Norfolk Island who wish to stay in the country as Soldiers or Settlers as in HRA, Series 1, Volume 1, p. 247.
 SRNSW Colonial Secretary’s Papers 1788-1825, Fiche 3267; 9/2731 p.67.
 Women off the Stores 16 June 1794 Norfolk Island, AJCP PRO CO/201/10, pp. 199 – 200.
 TNA, Item reference, WO 97/121/44.
 Sydney Gazette, 12 April 1822, p. 2.
 TNA, Item reference WO 97/930/95.