Mary of Lancaster [SEP] mother
Mary of Lancaster
Mary of Lancaster, Baroness Percy (1320 – 1 September 1362), was the youngest surviving child of Henry, 3rd Earl of Lancaster by his wife Maud Chaworth. Through her father, she was a great-granddaughter of Henry III of England.
Family.
Mary was born in 1320 or 1321. She was a sister of Henry of Grosmont, 1st Duke of Lancaster, Maud, Countess of Ulster, Joan, Baroness de Mowbray, and Eleanor, Countess of Arundel. Through her brother
mother Mary Anne Baker (b. Abt. 1792, England, d. 30 Sep 1831) were married on 16 Sep 1812 in St Margaret's Church, Rochester, Kent. Oliver was from Egerton in the county of Kent and Mary was from Tuddenham in the county of Suffolk. Available records indicate that Oliver and Mary had settled in West Malling by 1812.
William and Mary had issue; 
1. Alfred Usmar (b.22 Jul 1842, d. 6 Jun 1931) - The first Usmar in New Zealand (Wellington)