Number of years ago I read  a series of books about a society that was at war with what seemed to be a plant related species that was taking over the country.  The Prince of the “good guys” formed an alliance with an enemy
society, which were reptilian nature.  The prince transports them to his country on iceberg boats and together they defeat the enemy.  The Prince then allows the enemy society to remain in his counties  as allies and
friends even though they were different species.