From Germanic 'ragin' (counsel) and 'hari' (army), meaning 'army's counsel' or 'wise warrior.'
Rayner descends from the ancient Germanic compound Raginhari, built from ragin ('counsel,' 'decision') and hari ('army' or 'warrior') — making its core meaning something like 'wise warrior' or 'counsel-bearing soldier.' The name traveled into medieval Europe in multiple forms: Rainier in French, Reiner in German, Rayner and Rainer in English. It was carried into Britain with the Normans after 1066 and appears in medieval English records as both a personal name and a surname.
The name's most celebrated bearer is perhaps Saint Ranieri of Pisa (1117–1160), a patron saint of the city of Pisa, whose feast day involves one of Italy's most spectacular celebrations: the Luminara di San Ranieri, where ten thousand candles illuminate the Arno riverbanks. The name also belongs to Rainier III of Monaco, whose 1956 marriage to Grace Kelly was one of the defining royal spectacles of the twentieth century, briefly returning the name to glamorous visibility across the Western world. In the English-speaking world Rayner has lived quietly as both a given name and a surname for centuries, never quite fashionable but never extinct.
The spelling Rayner (versus Rainer) gives it an English-language legibility while retaining the name's continental dignity. It sits comfortably beside the current wave of interest in old Germanic and Norman names — think Archer, Garner, Thayer — and shares their sense of medieval solidity. Parents who find Rayner are usually looking for something that sounds vaguely familiar but isn't already claimed by a thousand children in every classroom.