One great book is 'The Magic Tree House' series. It takes young readers on adventures through different historical periods in a fun and engaging way. The simple language makes it suitable for beginning readers.
A wonderful historical fiction for beginning readers is 'Little House on the Prairie'. It gives a vivid picture of pioneer life in the past. The story is told in a way that young readers can follow easily, with descriptions of daily life, family relationships, and the challenges of living in a different time period.
Another option is 'I Survived' series. These books focus on various historical disasters and events. They are written in an accessible style that helps new readers understand historical concepts while being entertained. The short chapters also make it easier for those just starting to read.