Meanwhile Talleyrand was endeavouring to induce Great Britain to combine with France in a joint mediation between Austria and Russia at the congress, in the event of Russia demanding the duchy of Warsaw. Wellington, while expressing himself in favour of an understanding, refused to accept anything which might seem equivalent to a declaration in favour of mediation by the two powers in every case. At the congress itself Great Britain was first represented by Castlereagh, who was succeeded in February, 1815, by Wellington. The two principal difficulties were the questions of Poland and Saxony. The tsar desired to erect the duchy of Warsaw, Prussia's share in the two partitions of Poland in 1793 and 1795, into a constitutional monarchy attached to the Russian crown, while Prussia, though not unwilling to resign her claims to Polish dominion, wished to increase her territory by the incorporation of Saxony in her monarchy. Austria was naturally averse from any increase of strength in the states on her northern borders, and she was also opposed to the establishment of a constitutional monarchy in Poland which might serve as a centre for political discontent in her own dominions. Even France urged this objection to a constitutional Poland. Great Britain alone was willing to see an independent Poland, but preferred to join France, Prussia, and Austria in demanding its repartition between the two latter powers rather than its annexation to Russia. All through October Austria, Great Britain, and Prussia endeavoured to induce the tsar to withdraw his demand. Early in November he won over the King of Prussia to whom he promised the kingdom of Saxony, proposing to indemnify the Saxon king with a new state on that lower Rhine which France was not allowed to have, but which no other power desired. [Pageheading: _THE RETURN OF NAPOLEON._]