Aye you absolutely sure you are using the correct account name and password ? Ordinarily just clearing History will not prevent you using webmail. If you use the History option to forget about the site it would clear everything from the History of that site including: cookies, the site address and the login details * As explained here [[Delete browsing, search and download history on Firefox#w_how-do-i-remove-a-single-website-from-my-history]]'''_how-do-i-remove-a-single-website-from-my-history''' ** Other options clear fewer items: <s>[[Forget button - quickly delete your browsing history on Firefox]]</s> wrong article link [[Delete browsing, search and download history on Firefox#w_how-do-i-clear-my-history]]'''_how-do-i-clear-my-history''' In fact recording all the details then using the forget site option can be a good trouble shooting step to gain access to a site. Or try an alternative browser. If someone has taken control of your account you will need to that up urgently with Google. You will need your security details to hand. You may also need to consider what else may be compromised * For gmail security problems see https://support.google.com/mail/answer/50270?hl=en