Recorded as Monday, Munday, Mondy, Mundy, and possibly others, this interesting and unusual surname is usually of English origins, but in some cases can be Irish. If English it derives from the pre 7th century word 'mondaeg', meaning moon day, and in ancient times it was considered lucky to be born on this day, and this may be one of the origins of the name. A second possible origin is from the Old Norse personal name "Mundi", from mundr, meaning protection. A third possibility is feudal, and may have described a person who owed service to the local lord on a Monday. Finally it may be Irish from the Gaelic name 'Mac giolla Eoin', meaning 'The son of the follower (or friend) of Eoin'. It is said that in Ireland the surname was created by the confusion of the last part of the personal name with the Gaelic word 'luain' which means Monday. Early examples of the surname recording in the city of London are those of Alexander Munday, who was christened on October 9th 1633 at the church of St. Katherine by the Tower (of London), and the marriage of Adam Munday and Anne Roberts on December 31st 1682 at All Hallows, London Wall. The first recorded spelling of the family name is shown to be that of Richard Mundi. This was was dated 1239, in the cartulary or register of the monastery of Ramsey in Norfolk, during the reign of King Henry 111rd of England, 1216 - 1272. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as the Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.