The question of Bengal is a case that is very near from the German question, the German countries splitting in two nations: Germany and Austria. Basically, in history Bengal was cut in two parts, sharing the same language, but divided in what concerns the main ideology, which was, at this feudal time, religion.
Because of this and following the Marxist definition of nation, the separation of West and East Bengal is more near to the Germany/Austria split than to the West/East Germany separation of 1945-1989.
Let's see here how did the Bengali people evolve.
Bengal: the impossibility of Islamic mass conversion brought from outside
The reason of such a separation like the one that occurred in Bengal – with the formation of Bangladesh- can not be simply explained by mass conversions in the East Bengal brought by Islamic missionaries.
Islam arrived at the 12th century, through conquest on one side, through trade on the other, especially on the coastal area, with the port of Chittagong for example. Then, a lot of missionaries came to propagate Islam.
But this can not have made that, today, 90.4% of the population is of Islamic culture in Bangladesh.
a) First of all, we can see that this Islamic culture did not spread in that extend in the western part of Bengal. Yet, Islam did not begin as a stream trying to turn mainstream. It never had the particularities of a subculture, like it had in Hyderabad in Andhra Pradesh, where it is a kind of Islamic “Island”.
Because of this, the explanation that give a central role to Muslim Governors, Kings, Nizams, etc. and missionaries is not valid.
Islam was simply just accepted by the masses of eastern Bengal, and this in a massive way, from one day to another. The Bangla language was so left nearly untouched, staying strongly based on Sanskrit origin and by Aborigines borrows.
There was absolutely no process of building of a language like Hindustani, where what is today Hindi and Urdu borrowed massively Persian vocabulary and expressions, because of the major influence of Islamic culture.
The masses of Bangladesh even took this language question as a main weapon in their struggle against West Pakistan, a country where Islamic culture has the hegemony.
b) Then, we can see that Islamic Bengal was and is still today a small pocket, in a area of the world where Hinduism is still a main component of the ruling ideology: India.
Bengal was far away from the Islamic cultural centers; it was separated by numerous peoples and cultures; it was not in direct contact.
The British Empire tried to understand this reality, and the census made in 1872 showed that the Muslim pockets in Bengal were in the alluvial plains.
Seeing this, and that only a bit more than 1% of the asked people affirmed to have foreign origin, the British cadres thought that they were coming from the low castes, that converted to Islam to escape the rule of Hinduism.
But this explanation is mechanical. Bengal was before Islam indeed under Buddhist influence, and Buddhism knew no castes. There was also Jainism that existed in ancient India, where castes are not recognized.
Why should have the most oppressed masses chosen a religion coming from far away, if it was only for a question of caste, as they could just uphold Buddhism, like they did before?
The particular situation of Bengal
Dialectical materialism teaches us that the contradiction is in an internal process. So, the reason for the triumph of Islam in the eastern part of Bengal must come from Eastern Bengal itself.
Islam in Bengal can not have been “imported”.
So, let's take a look at the history of Bengal. We can see these interesting particular features:
a) Following the Manusmṛti, known in Europe as the Laws of Manu (between 200 BC and 200 AD), Bengal was not a part of Āryāvarta (Sanskrit: “abode of the Aryans”).
b) It was only under the Maurya Empire (321 to 185 BC) that the western part of Bengal was joined for the first time to ancient India, the eastern part forming the extremity of the empire.
c) It was merely during the Gupta Empire (320 to 550 AD) that the local chiefs were crushed in Bengal.
What does it mean? That under the Maurya Empire, (mainly western) Bengal knew a leap of civilization, notably through the great Buddhist emperor Asoka. Then, with the Gupta Empire and its extermination of Buddhism in India, Bengal became the last place of confrontation between Hinduism and Buddhism. Followed then a policy of missionaries promoting Hinduism.
It is clear that the Maurya and Gupta Empires changed the reality of western Bengal, developing its society to a higher stage, with a state administration produced by the high development in West India.
Because of this, the collapse of the Gupta Empire brought a situation of chaos in Bengal, a situation called “matsyanyaya”. A new dynasty knew locally a birth, the Palas, that put forward Buddhism – clearly to have a stronger balance of power with ancient India, that was under Hinduistic rule. Even in South East Bengal, local kings followed this pro-Buddhism policy.
But the Palas tried to invade some parts of ancient India, especially Bihar, on the West of Bengal. The center of gravity went to the west, sweeping away more and more from East Bengal. This should have had fatal consequences for Bengal's unity.
The source of the Bengal Split
At this thime, a Buddhist Bengal that would be a part of ancient India was not possible; the Hinduistic forces controlled the most of India, Bengal was dependent on it, and so the Hinduistic culture spread in all the Pala's culture.
The Palas kings were surrounded by a Hinduistic state apparatus (from poetry to ministers), married to women from Brahmin's families; in this process Western Bengal was attracted to ancient India, this time in a decisive manner. Buddhism was only maintained under the Palas, so that a distinct identity was kept, the rule of the Palas justified, and also because it was an expression of the Bengali culture of this time.
Indeed, the Bengali Buddhism was characterized by a massive presence of Goddess. We find for example these important figures, present in the Palas version of Buddhism
We will see that this massive presence of Goddess in the Bengali culture will help us in a significant manner.
Nevertheless, what counts here in this process, it was only a question of time until feudal forces - connected to hinduistic India - overthrew the Palas dynasty. This happened with Vijayasena, a Brahmine-Warrior from the south of India, that established an Hinduistic dynasty, integrating Buddha as an (evil) avatar of Vishnu.
The dynasty of the Senas pushed Hinduism forward in a massive manner, bringing Brahmins from the rest of India to build a new feudal ruling class, with the grants of land also. The Senas installed a small minority as a mere religious “elite”, in a very strong hierarchical way.
Bengal was basically colonized by Hinduistic ancient India; the impact of this colonization had of course a center of gravity in the western part of Bengal.
The dynasty of the Senas meant the ruin of trade of merchants, that upheld Buddhism – here the “equal” aspect of Buddhism shows his pre-bourgeois aspect, very near from protestantism, with also the stress on a global civilization and an unified administration.
For this reason, Bengal turned feudal, from the top of society, because of ancient India's influence.
We have here the main key of the split. Indeed, we can see here:
a) The Maurya and Gupta influence brought western Bengal to a higher stage of culture, whereas the eastern part remained back-warded but still influenced by aborigine culture and matriarchy;
b) Then, there was a historical chance for Bengal to unite – under the banner of Buddhism, like what happened in the countries at the East of Bengal (Burma, Laos, Thailand...). This unification would have been made by a kingdom mostly based in the western part and the generalization of trade.
c) But the Sena dynasty collapsed, because of the expansion of ancient India, and west Bengal became a part of it on the cultural and economical levels, which means that the feudal aspect triumphed over the pre-bourgeois aspects carried by Buddhism and the towns.
d) The Eastern part needed a qualitative leap, that was quite missed under the Maurya and Gupta empires, but it could not be bases on Buddhism, as it was the ideology of the Palas dynasty, whose foundation was in the western part or even in Bihar.
e) The Islamic invasion arrived exactly at this time of a general need of an anti-feudal movement.
f) Nevertheless, the anti-Brahmin pre-bourgeois movement will then not only present in the East, with Islam – it will exist also in the westen part of Bengal, through Goddess worship that was already present in Buddhism, and that was put in Hinduism.
A new dynamic
Bourgeois historians think that mass conversion of Islam was a peasant reaction to the aryan penetration in Eastern Bengal; in fact, Islam in the East and Aborigines – influenced Hinduism in the West were both pre-bourgeois expression against feudalism.
The bourgeois historians noticed that the peasants were too weak on the economical level, but think they tried to fight on the ideological and cultural fields, through the weapon of Islam borrowed from the outside.
It would mean that the peasants were an unified and conscious class – what never was the case in history. In fact, pre-bourgeois classes build an ideological weapon to counter-attack against the feudal penetration in Bengal.
The Islamic invasion – which was not an invasion but a conquest – was the detonator of this historical moment of class struggle.
In Eastern Bengal, Islam was massively accepted. But this Islam was specifically Bengali. There was an overemphasizing on the magical aspects of the missionaries that brought Islam. Those “Sufis” were considered to cure illness, walk on water, etc.
Even if Islam in Bangladesh is Sunni, in a unique manner it celebrates saints, tombs are occasion of pilgrimages, etc.
In the same way, Hinduist and Buddhist sites were simply adapted to the Islamic cult.
In Western Bengal, hinduism became hegemonic, but it was also altered. The main manner to consider Hinduism is kali-kula – the cult of the great goddess (Mahadevi) or of the goddess (Devi), also known as shaktism.
Satyajit Ray's movie “Devi” depicts this reality; in Bengal, the goddess Kali is revered, and shaktism can be considered stronger as Saivism and Vaishavism, that represent much more typical aspects of the Indo-Aryan patriarchal culture and ideology.
So, in West and Esat Bengal, Hinduism celebrates goddess like Durga, Kali, Lakshmi, Sarasvati, Manasa, or Shashthi, Shitala, Olai Chandi.
But this is not all. Syncretism appeared here as the Bengali national tendency to unite.
As West Bengal turned into a variant of Hinduism and East Bengal turned to a variant of Islam, and because the unity was still great between those two parts of the world, a syncretic tendency developed itself.
It was clearly an expression of the pre-bourgeois elements, that tried to unite and not to divide; because of this bourgeois aspect, the expression was universalist.
In the western part, Chaitanya Mahaprabhu (1486–1534) developed a cult of Krishna as only real god and above the casts, based on “love” in a mystical union with the absolute truth ; in East Bengal, the sufis taught the central character of love to join God, beyond the formal aspects of religion.
In this Islamic case, the sufis adopted the position of the gurus in Hinduism and Buddhism, teaching the way of truth to the disciple, through meditation in particular.
The main question was then: would both tendency finally join themselves? Or would these tendencies follow particular paths, modifying the psychological characters in two divided parts, giving birth to two different nations?