Repetition is a critical issue in interpreting the work of Herodotus. Detlev Fehling, for one, has pointed to recurrence of motif and scene as evidence of the historian’s ‘free invention’. Words that occur twice in Herodotus are an efficient way to consider pressing issues at the centre of how and why Herodotus put together his narrative in the way he has. Pairs where the uses are close together in stories with a lot in common suggest that we may be seeing Herodotus’ ‘habit of presentation’, especially when phrasal repetition is also found. Where pairs are found further apart, the issue of deliberate linkage between discrete episodes may be indicated through the strategic redeployment of a key term. Finally, with Xerxes’ invasion, recurring terms help us to see how Herodotus could operate over large portions of text, deliberately linking one episode to another through the deployment of twice-occurring words, thereby also connecting the whole account of the campaign to the largest project of the History.