Historically, the order of precedence had been a matter of great dispute. European powers agreed that the papal nuncio and imperial ambassador would have precedence, but could not agree on the relative precedence of the kingdoms and smaller countries. In 1768, the French and Russian ambassadors to Great Britain even fought a duel over who had the right to sit next to the imperial ambassador at a court ball. After several diplomatic incidents between their ambassadors, France and Spain agreed in 1761 to let the date of arrival determine their precedence. In 1760, Portugal attempted to apply seniority to all ambassadors, but the rule was rejected by the other European courts.