title: Retrieving latitude/longitude coordinates for cities/countries that have since changed names?
body: <p>Say I have a vector of cities and countries, which may or may not include names of places that have since changed names:</p>
  
  <pre><code>locations &lt;- c("Paris, France", "Sarajevo, Yugoslavia", "Rome, Italy", "Leningrad, Soviet Union", "St Petersburg, Russia")
  </code></pre>
  
  <p>The problem is that I can't use something like <code>ggmap::geocode</code> since it doesn't appear to work well for locations whose names have changed:</p>
  
  <pre><code>ggmap::geocode(locations, source = "dsk")
  
         lon      lat
  1  2.34880 48.85341 #Works for Paris
  2       NA       NA #Didn't work for Sarajevo
  3 12.48390 41.89474 #Works for Rome
  4 98.00000 60.00000 #Didn't work for the old name of St Petersburg  seems to just get the center of Russia
  5 30.26417 59.89444 #Worked for St Petersburg
  </code></pre>
  
  <p>Is there an alternative functions I could use? If I have to "update" the names of the cities &amp; countries, is there an easy method of going through this? I have hundreds of locations that I was looking to collect the longitude and latitude coordinates.</p>