Well I suppose maybe it was really the beginning of 'poverty' as we know it in the modern sense, as the modern working class and the modern landlord/commercial/capitalist class were being created simultaneously by the same process.
With one small group accumulating vast pools of private capital and the other large group now landless and without subsistence, the stage was perfectly set for the wage labor system, in which workers were compelled to rent out their labor in exchange for subsistence wages. It's the principle of social organization that dominated during the industrial revolution and is continuing straight through into the post-industrial age.
But there isn't any particular reason why it had to happen that way or why it needs to be that way now. Our modern social and economic system is the result of particular historical events, including especially the English land enclosures. Remembering this can help us to understand that the wage-work system has not always existed and other forms of social and economic organization are possible and maybe preferable.