Reasons for desertion

• Climatic change - several calamitous harvests from 1272 on, the end of the Medieval Warm Period
  Medieval Warm Period
  The Medieval Warm Period , Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region, that may also have been related to other climate events around the world during that time, including in China, New Zealand, and other countries lasting from...
  
   followed by a persistently wetter and cooler climate from 1300, and disastrous years in 1317-9. Great variability in the weather, notably the seven day storm of January 1362
  Grote Mandrenke
  The Grote Mandrenke was the name of a massive southwesterly Atlantic gale which swept across England, the Netherlands, northern Germany, and Schleswig around January 16, 1362, causing at minimum 25,000 deaths. January 16 is the feast day of St...
  
  .
• Agrarian blight - land that had previously been the most fertile (especially toward the north-east of the county) had been overfarmed. The rise of grain prices following climatic change led to a preference for arable farming over stock. Stock levels also fell due to murrain
  Murrain
  Murrain is a highly infectious disease of cattle and sheep. It literally means "death" and was used in medieval times to represent just that. The population of that era had no way of identifying specific diseases in their livestock so they simply put all illnesses under one heading...
  
  . The consequent lack of manure from stock let to the land's fertility declining. See Great Famine of 1315-1317 and the List of famines.
• Black Death
  Black Death
  The Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. Of several competing theories, the dominant explanation for the Black Death is the plague theory, which attributes the outbreak to the bacterium Yersinia pestis. Thought to have...
  
   (1348-9)
• Migration - village relocates to be nearer major road in order to exploit passing trade, as Stevenage
  Stevenage
  Stevenage is a town and borough in Hertfordshire, England. It is situated to the east of junctions 7 and 8 of the A1, and is between Letchworth Garden City to the north, and Welwyn Garden City to the south....
  
   did in regard to the Great North Road. The new location positioned it to be an obvious choice for the core of one of the country's first new towns
  New towns in the United Kingdom
  Below is a list of some of the new towns in the United Kingdom created under the various New Town Acts of the 20th century. Some earlier towns were developed as Garden Cities or overspill estates early in the twentieth century. The New Towns proper were planned to disperse population following the...
  
  .
• Pasture - the switch to pasture, exemplified by the enclosure
  Enclosure
  Enclosure or inclosure is the process which ends traditional rights such as mowing meadows for hay, or grazing livestock on common land. Once enclosed, these uses of the land become restricted to the owner, and it ceases to be common land. In England and Wales the term is also used for the...
  
  s, required less manpower, leading to the decline of village life.
• Landscaping - village destroyed or relocated to create parkland for a noble's house. Pendley, destroyed soon after 1440 for Sir Robert Whittingham. Kitts End was incorporated in the Byng
  John Byng
  Admiral John Byng was a Royal Navy officer. After joining the navy at the age of thirteen he participated at the Battle of Cape Passaro in 1718. Over the next thirty years he built up a reputation as a solid naval officer and received promotion to Vice-Admiral in 1747...
  
   (Viscount Torrington
  Viscount Torrington
  Viscount Torrington is a title in the Peerage of Great Britain. It was created in 1721 for the statesman Sir George Byng, 1st Baronet, along with the subsidiary title Baron Byng, of Southill in the County of Bedford, also in the Peerage of Great Britain. He had already been created a Baronet, of...
  
  ) family's Wrotham Park estate in the 19th century having dwindled after the construction of a new Barnet
  Barnet
  High Barnet or Chipping Barnet is a place in the London Borough of Barnet, North London, England. It is a suburban development built around a twelfth-century settlement and is located north north-west of Charing Cross. Its name is often abbreviated to Barnet, which is also the name of the London...
  
   - Ridge Hill
  Ridge, Hertfordshire
  Ridge is a village and civil parish in the Hertsmere borough of Hertfordshire, situated between Potters Bar and Shenley. It has a small church, St Margaret's and a small playground. There is a public house called the Old Guinea which serves food on most days. The village also holds a fete day on...
  
   road in 1826.
• Urban growth - the growth of Baldock
  Baldock
  Baldock is a historic market town in the local government district of North Hertfordshire in the ceremonial county of Hertfordshire, England where the River Ivel rises. It lies north of London, southeast of Bedford, and north northwest of the county town of Hertford...
  
  , Buntingford
  Buntingford
  Buntingford is a small market town and civil parish in the district of East Hertfordshire and county of Hertfordshire in England. It lies on the River Rib and on the Roman road Ermine Street. As a result of its location, it grew mainly as a staging post with many coaching inns and has an 18th...
  
  , Royston
  Royston, Hertfordshire
  Royston is a town and civil parish in the District of North Hertfordshire and county of Hertfordshire in England.It is situated on the Greenwich Meridian, which brushes the towns western boundary, and at the northernmost apex of the county on the same latitude of towns such as Milton Keynes and...
  
  , St Albans
  St Albans
  St Albans is a city in southern Hertfordshire, England, around north of central London, which forms the main urban area of the City and District of St Albans. It is a historic market town, and is now a sought-after dormitory town within the London commuter belt...
  
   and others with markets
  Market town
  Market town or market right is a legal term, originating in the medieval period, for a European settlement that has the right to host markets, distinguishing it from a village and city...
  
  or monastic premises seems to have sucked the life from several villages nearby.