Simplify the following text for a Grade 10 native English-speaking person.
Original: She was accompanied by her mother whose presence was necessary to satisfy the requirements of David Anstey , chief warden , who was concerned for their safety ; Tanzania was `` Tanganyika '' at that time and a British protectorate .
Simplified: She was accompanied by her mother whose presence was necessary to satisfy the requirements of David Anstey , chief warden . He was concerned for their safety ; Tanzania was `` Tanganyika '' at that time and a British protectorate .