Hamoud became sultan with the support of the British consul, Sir Basil Cave, upon the death of Hamad bin Thuwaini. Before he could enter the palace, another potential contender for the throne, Khalid bin Barghash seized the palace and declared himself sultan. The British responded at 8:00 am the next day, August 26, 1896, by issuing an ultimatum to Khalid and his entourage to evacuate the palace within one hour. When he refused, British warships fired on the palace and other strategic locations in the city, destroying them and causing Khalid to flee. According to the Guinness Book of World Records it was the shortest war in history, and the following day Hamoud was able to assume the title of sultan, more indebted to the British than ever.
Hamoud complied with British demands that slavery be banned in Zanzibar and that all the slaves be freed. For this he was decorated by Queen Victoria and his son and heir, Ali bin Hamoud, was brought to England to be educated. Ali died in 1902 and was succeeded by Ali.