Brianna,
Hello, my name is Jared Foster, Webmaster for FosterQuest. I am very familiar with the history you are referring to. It's really not 100% proven to be factual. But it is widely accepted and believed by many Foster and Forrester Historians. In school I also had a very similar assignment in 8th grade. I hope that this information will help. This is the link to my History Web Page that shows this information and some coats of arms (Heraldic Symbols) that the Foster and Forresters have been subject to. Keep something in mind. Sir Richard Forrestarius was from Flanders as was his sister, Queen Matilda, wife to William The Conqueror. This being true we are Flemish by ancestry. Most of our history after the Norman Conquest was in Scotland until the 1400's. We are of Scottish descent as well. To know more about our Scottish ancestry go to www.forresterfamily.org. This is the Scottish Clan Forrester website. We have had several Knights, Sherrifs, Lords and other renowned titles in English and Scottish History. We have a few Castles in our history.
Pre Norman Conquest
Our ancestry can be traced back proir to the ninth century. In 862 ad, Count Baldwin I, "Iron Arm", of Flanders began his rule in Flanders. He ruled 862 - 879 AD. Count Baldwin II, "TheBald", of Flanders ruled Flanders 879 - 918 AD. Count Baldwin II named his first-born son Arnulf to denote royal ancestry as "Saint Arnulf of Metz" (ruled in the Carolingian Royal House) was an ancient ancestor. Count Arnulf I, "The Elder", of Flanders ruled 918 - 964. During his reign his son Baldwin III died thus his thrown was succeeded by Count Arnulf II, of Flanders who ruled 964 - 988. Count Baldwin IV, "The Bearded", of Flanders, succeeded his father's thrown and ruled 988 - 1037. Count Baldwin V began his rule in 1037. During his rule he sired two children of high significance to us. Matilda, who became the wife of Duke William, of Normandy, and Richard, The Forester, of Flanders. This is where our surnames have thier beginning.
The Norman Conquest
During the reign of King Edward III, "The Confessor", of England, Duke William King of Normandy, visited England. Count Baldwin V (his father-in-law) and Richard, "The Forester" (his brother-in-law) accompanied him in this visit. It was on this visit that King Edward III, who had no children, promised the throne to his cousin, Duke William. Duke William returned to Normandy holding this promise. In 1066 King Edward III deid with no heirs. Quickly, his brother-in-law, Harold laid claim to the throne and was crowned. King Harold had previously sworn allegiance to Duke William and swore to support his claim to the throne. The news came as a shock to Duke William. Immediatley, William gathered his forces of Norman Knights and set sail for England. Sir Richard, The Forester, who was only sixteenyears old, was amoung these knights. Shortly after thier landing then famous "Battle of the Hastings" took place. It was during this battle that King Harold was killed. William would now be known as King William I, "The Conqueror", King of England. He was crowned on December 25, 1066.
Our Surname Begins
After King WIlliam I took the throne that he was promised, Sir Richard, The Forester settled in Northestern Enlgand where he was granted land. The latinized name the Sir Richard was called by was Forestarius. He soon changed it to the english name Forester. Five generations later, some of his descendants were surnamed Forster (Sir Randolf Forster) and seventeen generations later some were known by the surname Foster (Richard Foster).
This link is for a great site that discusses Foster/Forster/Forrester History.
http://gerryforster.netfirms.com/History/Forster_History_1.htm