British pressure forced Ismail into the 1877 slave-trade abolition treaty granting UK enforcement rights.

Evidence

The farther south Ismaïl moved, therefore, the more vigilant the influential members of the Anti-Slavery Society became. Not only did they petition the khedive directly to abolish the slave trade, but they also had the ear of many individuals in Parliament and the Foreign Office. So loud were their voices that, by 1877, Ismaïl signed the Anglo-Egyptian Slave Trade Convention. Under the terms of this treaty, Isma`ïl committed Egypt to abolition of the trade in African slaves, particularly those from the Sudan and Abyssinia. The treaty also permitted the participation of British forces in this campaign to end the slave trade. — Eve M. Troutt Powell, A Different Shade of Colonialism_…, 295

Categorization

• ADDENDUM: Relevant to the sacrifice article in that it shows how a sovereign can be pressured into formal concessions; more centrally, it shows European leverage reshaping Egyptian sovereignty in Sudan ahead of occupation.
• XREF: connects to: Khedive Ismail borrowed heavily on unfavorable terms from European banks