Hamza bin Abdul Muttalib
Are both Imam Hussain (AS) and Hamza Abdul Muttalib (R) known as Sayyid al-Shuhada? If so, is there a difference between them in regards to this title?
Hamza ibn Abdul Muttalib was Sayyid al-Shuhada in his time. Imam Husain (AS) is Sayyid al-Shuhada for all the times till the Day of Judgement.