open the .bashrc file as follows:

root@linuxhelp:~# vim .bashrc

Edit the following changes inside the bashrc file,search for HISTSIZE and change the number that you would want to list in the history.Here I have set 100 as my count so that it prints out the last 100 executed commands.

HISTSIZE=100
HISTFILESIZE=5000

Then Reload the .bashrc file through the below command.MAke sure you run this.
root@linuxhelp:~# source ./.bashrc