History of PageRank
PageRank is the mathematical formula that is one of the original basis for Google's search engine. It was first introduced when the current CEO was attending Stanford University. Here
is the original paper about the background of PageRank.
Tools where you can see historical pagerank
There have been quite a few tools where you can discover historical PageRank of a site. Currently, only www.urltrends.com
is reliable and keep updating the PageRank in a timely manner.
When was the last Google Pagerank update?
There are quite a few sites keeping track on Google PageRank updates.
Google used to update PageRank every 3-6 months, but there are indications that it can happend more seldom in the future. One of the main reasons that SEOs and webmasters estimate that Google update
Pagerank more rarely is because of the fast growing Google's index. The more pages included in their webindex, the longer time it takes for them to spider it all. The last Google algorithm update was
done the 4th of February, 2013. Many webmasters estimate a new update will roll out in September or latest October 2013. More info at Hobo-web.co.uk
or you can download
firfox or chrome plugins to follow the PageRank of any website you like.