 The new capital Hangzhou grew into a major commercial and cultural center . It rose from a middling city of no special importance to one of the world 's largest and most prosperous . During his stay in Hangzhou in the Yuan dynasty ( 1260 – 1368 ) , when the city was not as wealthy as it had been under the Song , Marco Polo remarked that " this city is greater than any in the world " . Once retaking northern China became less plausible and Hangzhou grew into a significant trading city , the government buildings were extended and renovated to better befit its status as an imperial capital . The modestly sized imperial palace was expanded in 1133 with new roofed alleyways and in 1148 with an extension of the palace walls . 
 The new capital Hangzhou grew into a major commercial and cultural center . It rose from a middling city of no special importance to one of the world <a href='null_genetive' title='1'><mark>'s</mark></a>largest and most prosperous . During his stay in Hangzhou in the Yuan dynasty ( 1260 – 1368 ) , when the city <a href='negative_concord' title='2'><mark>was</mark></a> <a href='negative_concord' title='3'><mark>not</mark></a>as wealthy as it had been under the Song , Marco Polo remarked that " this city is greater than any in the world " . Once retaking northern China became less plausible and Hangzhou grew into a significant trading city , the government buildings <a href='uninflect' title='4'><mark>were</mark></a> extended and renovated to better befit its status as an imperial capital . The modestly sized imperial palace was expanded in 1133 with new roofed alleyways and in 1148 with an extension of the palace walls . 
The new capital Hangzhou grew into a major commercial and cultural center . It rose from a middling city of no special importance to one of da world  largest and most prosperous . durin his stay in Hangzhou in the Yuan dynasty ( 1260 – 1368 ) , when the city ain't as wealthy as it had been under the Song , Marco Polo remarked dat " this city is greater den any in the world " . Once retaking northern China became less plausible and Hangzhou grew into a significant trading city , the government buildings was extended and renovated to better befit its status as an imperial capital . Tdamodestly sized imperial palace was expanded in 1133 with new roofed alleyways and in 1148 w/ an extension of thdaalace walls .