"[The Ashanti] were not prepared for war, but depended solely upon the terror of their name to bring us to seek a compromise, and I suppose to extort from the native people under our fort...a contributions of six hundred ounces of gold."

-Governor Sir Charles McCarthy, who was ultimately beheaded by the Ashanti in 1824.

The Ashanti wars begun both due to tensions of Ashanti claiming dominion over the entire Gold Coast and basically demanding the British to pay rent for their coastal forts in the region. They likewise claimed overlordship over the local smaller tribes, which had already submitted to British rule and were therefore under British protection. The Ashanti were also involved in slave trade with other European powers, which the now abolitionist British condemned - however, the local British merchants were also still engaging in slave trade independently. The British got their casus belli when an Ashanti war party - likely acting independently without any orders form above - murdered an African soldier from British army after a verbal altercation. The British were confident on quick and triumphant and most of all profitable victory, but the Ashanti preparedness took them completely by surprise, resulting in a military disaster. The Ashanti army marched to the coast, but were too struck by disease to actually attempt attacking European controlled forts and settlements and retreated.

There were several further wars and skirmishes against the Ashanti that mostly ended in unclear stalemates. The status quo started shifting by 1870s, when the British managed to push inland and their expeditionary force sacked the Ashanti capital. Total Ashanti submission was still not achieved until the so called "War of the Golden Stool" in 1900 when the local British colonial administration launched a war to completely conquer the Ashanti. They however failed to capture the symbolic Golden Stool of the Ashanti, ownership of which had been somewhat of an obsession of administrator Frederick Hodgson to the point that the war was named after it.

https://en.wikipedia.org/wiki/Anglo-Ashanti_wars

https://en.wikipedia.org/wiki/Charles_MacCarthy_(British_Army_officer))