This is a variant spelling of the Germanic pre 7th Century personal name "Ragin-Bald" and normally found in the spellings (as a surname) of Rambaut, Raimbauld, Rembaud and the English - Rainbow. The name translates as "Bold-Counsel" and is typical of the twin element compound names used by both the Germanic and Viking-Scandinavian peoples in the post Roman (circa 410 A.D.) period. One of the earliest recordings is that of Elsa Rambaegh who married Heinrich Daalmans on January 1st 1635 at Billerbeck Catholic Church, Westfalen, although the earliest spelling as "Rambadt" is shown below. Other recordings include Johann Rambadt, the son of Dietrich (below), who was christened at Pannekow, Mecklenburg, on August 26th 1810, and Carl Ludgwig Christian Rambadt who married Elizabeth Berner at Sophiehof Loitz, Pommern, on November 17th 1871. They had a daughter called Martha born on September 20th 1872, although we have no further details. The first recorded spelling of the family name is shown to be that of Dietrich Rambadt which was dated June 1st 1799, marriage to Ida Franz, at "Alt Kalen, Mecklenburgschwerin, Germany", during the reign of Emperor Francis 11 of the Holy Roman Empire, 1792 - 1806. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.