Possible Clues:

• Up about a drink from the river
• Reign over this Republic
• Reverse of fashionable country, with many leaving country
• This river's African Queen nearly capsized
• Is the boy back in the river in Africa?
• African country and river
• 22 across (anag) — northwest African river
• Monarch almost overthrown to create republic
• Country drink knocked back by monarch
• West African country, capital Niamey