Prince Owusu Ansah and his cousin Owusu Nkwantabisa were delivered to the British in Cape Coast as part of the peace treaty with George Mclean on April 27, 1831. They were later sent to Britain educated and converted to Methodism under the guidance of George McLean. They returned to Ashanti in 1841 with the mulatto Wesleyan missionary Freeman and Brooking, another missionary. They began their work as missionaries in a very ambivalent environment. In November 1841 a small Methodist school and congregation was started in Kumasi and in the period between 1840 and 1850 the prince became an active promoter of the Methodist faith up to late December 1862. He functioned alone in this role in an environment in which Christianity was viewed with great suspicion. By 1850 Ashanti British diplomatic relations had soured and all European missionaries left Kumasi. From then Owusu – Ansah was left to carry-on single-handedly his missionary work until 1852 that Reverend Timothy Laing arrived in Kumasi to help the prince with the religious task. In April 19, 1853 the river and those ones I was stationed at Abakrampa which was the capital of the Fanti state of Abura, where he was a full-time Methodist minister in the Gold Coast District for the Wesleyan mission. In August 1854, Reverend Thomas Freeman who was the head of the Methodist Church in the Gold Coast appointed Owusu -Ansah as superintendent of Cape Coast schools. After his years as a pioneer of converting Asante to Christianity, he became more involved in Ashanti-British diplomacy. During the period in which he lived in Cape Coast, in 1873, the 6th Ashanti war broke out and with the British unprepared, the Ashantis were soon within 30 miles of Cape Coast. All Ashantis on the coast were suddenly suspected of aiding the enemy. In the book "The history of the Gold Coast and Ashanti" by Walton Claridge published in 1915, he reports that "this situation was the principal because the most disgraceful outrage in that town. A proclamation had been issued on 17 February 1873 setting forth that the government would not guarantee the safety of any Ashantis living within the Gold Coast protectorate. It warns them that if they remained they would do so at their own risk. It seems however that an exception was made in the case of those who had been living on the coast for any length of time, provided of course they behaved themselves. The news of the battle of Fanti Yankumasi and the near approach of the enemy, however, greatly alarmed and enraged the people of Cape Coast, who for some time past had been suspicious of Prince Owusu - Ansah on account of his nationality, and believed or professed to believe that he was secretly supplying the Ashantis with ammunition and at 2:30 on the afternoon of Sunday, 16 March mob led by W.E. Davidson, James Brew and James Amissah went to his house, seized some of his Ashanti servants, one of whom had been living in the protectorate for more than 22 years and dragged them to the beach. There, the heads of the four of these men were hacked off with cutlasses, one of the executioners being a woman. Some officers from the castle were seen approaching the spot and the crowd dispersed, taking the heads of the victims with them; but while the officers were still standing over the bodies, they returned, dragging yet another prisoner with them, and before anything could be done to hinder them, he too had been beheaded. In the meantime another party had wrecked and plundered Owusu-Ansah's house, and he and his wife and child being compelled to barricade themselves in an upper room or they too would probably have been murdered. Armed police were sent out to protect him and he was brought to the castle and lodged there for their safety; but public feeling against him run so high that a strong escort was needed again the next day when he went to the inquest. Evidence of willful murder was returned against some persons unknown but nothing more was ever done to punish the perpetrators for this outrage.
Although it was known that Davidson Brew and Amissah were the ring leaders who had headed the mob at Owusu-Ansah's house, it was found that it would be impossible to prove their presence on the beach or that they were privy to any intention to murder when they went to Ansah's house. It was also felt that the public feeling on the matter was so strong that there was no reasonable prospect of obtaining a conviction, even for a riot, from any jury that might be assembled in Cape Coast, and subsequently no proceedings were instituted against them. They were officially informed however that "Her Majesty's Government viewed with displeasure their participation in these disgraceful proceedings which led to the barbarous murder of five Ashantis that in ordinary times, it would have been the duty of the government to take steps to punish them for their part in the riot; but that, looking at all the circumstances of the moment, and the natural excitement and anger caused by the invasion, the government had refrained from giving directions for persecution." How much effect this intimation was likely to have on the three men concerned must be a matter of opinion but it speaks well for the king of Ashanti and goes a long way towards proving the honesty of his intentions that he did not immediately execute the missionaries and Fantis he had in Kumasi in revenge for these murders of his subjects. The people still had one of the wives of Kotiko the Ashanti ambassador and the boy in their power but they were given up a few days later and Prince Ansah was sent to Sierra Leone on 16 April for his own safety. Although his removal had been kept secret, it was discovered just as the boat pulled off to the steamer and a dense crowd of women assembled on the beach and denounced and cursed him with their customary force and fluency."
By 1878 he had returned to Kumasi and was acting as an adviser to King Mensa Bonsu and was thought to have deceived the king and given advantage to the British through forged documents. He continued with his diplomatic roles for Ashanti until his death in Cape Coast on 13 November 1884. Prince Owusu-Ansah was an example of an Asante royal who believed that the embrace of Christianity would not only enhance the spiritual power of Asante but would also bring peace.