In Jyoti Basu's death, the CPM has lost its voice of reason. And at the end of the Basu era, CPM  faces a number of challenges.

The CPM is mourning the loss of its patriarch. Jyoti Basu's demise not only marks an end of an important chapter in India's politics and the communist movement but also presents future challenges for the Left.

"His precious legacy is there for us to cherish and nurture. We pledge to carry forward his cause and work," said Sitaram Yechury, Polit Bureau member.

For the Left the biggest challenge is to retain what Basu and his colleagues built over three decades - the red fort in West Bengal.

Basu's dominance was so complete that it left little space for the Opposition in Bengal.

But even the worst Left critic had words of praise for Basu's political acumen.

"Towards the end, my relationship with him was good and we discussed politics and political movements," said Mamata Banerjie, Union Railway Minister.

Basu stepped down to hand over the reins to Buddhadeb Bhattacharjee in 2000. But his party forced him to continue as a Polit Bureau member.

In the last few years, he has seen the Left going through its most turbulent phase both in Bengal as well as well as at the national level. From its best ever performance in the 2004 Lok Sabha polls, the Left suffered its worst ever electoral defeat last year.

Be it the Nuclear Deal, the Left's souring of relations with the Congress, the expulsion of Somnath Chatterjee or urging for restraint during Nandigram and Singur.

"Personally it was a great fortune for me to receive his love. He was a leader for everyone. He was a leader of the masses," said Somnath Chetterjee, former Speaker.

Basu was the only surviving member of the first Polit Bureau of the CPM. Now the present leadership will not only have to retain the party's legacy but also meet the future challenges.