Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: In 1700 several hundred French Huguenots migrated from England to the colony of Virginia, where the English Crown had promised them land grants in Lower Norfolk County. When they arrived, colonial authorities offered them instead land 20 miles above the falls of the James River, at the abandoned Monacan village known as Manakin Town, now in Powhatan County. Some settlers landed in present-day Chesterfield County. On 12 May 1705, the Virginia General Assembly passed an act to naturalise the 148 Huguenots still resident at Manakintown. Of the original 390 settlers in the isolated settlement, many had died; others lived outside town on farms in the English style; and others moved to different areas. Gradually they intermarried with their English neighbors. Through the 18th and 19th centuries, descendants of the French migrated west into the Piedmont, and across the Appalachian Mountains into the West of what became Kentucky, Tennessee, Missouri, and other states. In the Manakintown area, the Huguenot Memorial Bridge across the James River and Huguenot Road were named in their honor, as were many local features, including several schools, including Huguenot High School. Question: When were these settlers naturalized as English colonists?
12 May 1705