Probably the first emigrant Gherardini was Otterus, or Othoer, son of Mathias, a son of Cosmus, the great Duke of Florence. They were also of the Ferrara-Modena branch of the House D'Este, the younger branch penetrating to the Teutonic domains of Charlemagne to found the royal families of Brunswick and Hanover in what is now Germany. Some records say that Otho went to Normandy in the caravan of King Canut of England who had passed through Florence on his way home from a pilgrimage to Rome. It is said that he came into England later with Edward the Confessor when he was called back from exile to be King of England. There is an old lyric quote in English records which says "the Earldom which to Otho brave, the Saxon sainted Edward gave". His son, Otho Fitz-Othoer appears in 1058 in the Domesday Book as a baron of England.

 This man, Otho, was the ancestor of Gerald de Windsor. Gerald was the ancestor of the Fitzgeralds, Fitzmaurices, Carews, Redmonds and Keatings of Ireland, among others. Otho was so powerful that his favor with the King was greatly resented by the native Norman nobles. He possessed three lordships in Surrey, three in Buckinghamshire, two in Berkshire, four in Middlesex, nine in Wiltshire, two in Hampshire, three in Dorset, and one in Somerset. With him, the family name was changed to Geraldini. Otho's son, Walter fitz-Otho Geraldini, was treated as a fellow countryman by the Normans after the conquest of England in 1066. He succeeded to all of Otho's estates and his name is shown in the Domesday Book of 1087 that listed all the landholders of England. Windsor Castle, a great gray pile overlooking the Thames, had just been built amid the forests of Berkshire, and Walter was appointed its first castellan, as well as warden of the forests. He was, it is clear, one of the most Norman of the Normans -- a race renowned for its adaptability, no less than for its valor and ferocity.

Windsor Castle continued as a baronage for Otho's descendants for centuries, until it passed out of existence due to lack of male heirs in the direct line. An interesting footnote is the story of how the current English royal family, the House of Windsor, took their name from this vacated baronage. During the First World War, there was enormous anti-German sentiment in England, and the king wanted to distance himself from the German House of Hanover, their name at the time. Since the Gherardini family can be traced as the founders of the House of Hanover, it was very convenient that Gerald de Windsor, baron of England, was related both to the English royal family and the Florentine Gheradinis, and hence the House of Hanover (see above). This provided justification (after much research) for the German House of Hanover to become the more politically-correct English House of Windsor, which they remain to this day.

The Normans at this time were the foremost race in Christendom. Their courage and ruthlessness had made them conspicuous among the rovers from Scandinavia who ravaged Western Europe. They conquered and settled in Gaul (Normandy, means Northmen-land or land of the Norsemen). In Normandy, they founded a mighty state that terrorized every land from Spain to Germany. They embraced Christianity, adopted French and Latin as languages, and set up a feudal system. They were born soldiers, and their conquests extended to southern Italy, Sicily and the British Isles.

Having defeated the English at the Battle of Hastings in 1066 and placed their leader, William the Conqueror, on the throne of England, the Normans were not content with just subjugating and portioning out England among the captains of the invaders. They proceeded to invade Wales and conquered it within a year. Here they were purely conquerors, since William had some claim to the English throne, and he had none to Wales. His barons went there simply to seize and possess the land. The methods they adopted were not wholly military; they were also matrimonial.

Keating, Robert. "Otho." 18 Dec 2003. http://www.robertkeating.com/otho.htm