Complex sentence: This switching back and forth devalued Charles'position as a trustworthy ally while the return to the French alliance increased Godoy's unpopularity and strengthened "partido fernandista", the supporters of Crown Prince Ferdinand, who favoured a close relationship with the United Kingdom.
Split into simpler sentences: This switching back and forth devalued Charles'position as a trustworthy ally. The return to the French alliance increased Godoy's unpopularity and strengthened "partido fernandista", the supporters of Crown Prince Ferdinand, who favoured a close relationship with the United Kingdom.