This unusual name is of Anglo-Saxon origin, and is an English locational surname from the place called Blackler in Devonshire. The "black" element of the name is from the Olde English pre 7th Century "blaec", a common prefix to placenames of streams and hills in particular, and means "dark-coloured", or "dense" when used of woods or forests. The second element "-aller" is probably from the Olde English "alor" meaning "alder", so the surname Blackler or Blackaller means "one who lives by the dense alder wood". Locational names, such as this, were usually bestowed on those people who left their original habitation and went to live or work in another village or area. The variation in spelling from Blackler to Blackaller, can be seen in the following record of Wills in Devonshire in 1693: John Blackaller alias Blacklawe. Recordings from Devonshire Church Registers include, the christening of John, son of William Blackler, on July 31st 1572, at Totnes, and the marriage of Edward Blackler and Elsabeth Soper on September 18th 1575, also at Totnes. The first recorded spelling of the family name is shown to be that of John Blakaller, which was dated 1431, in the "Catalogue of Ancient Deeds of Devonshire", during the reign of King Henry V1, known as "The Founder of Eton", 1422 - 1461. 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.