Recently, we have witnessed a trend that many industries are forming consortiums and attempting to accelerate efficiency and reduce cost by using blockchain technology. Nevertheless, there is a clear missing capability of cross-industry and cross-blockchain interoperability. Currently, most blockchain business networks operate in isolation without external data transfer or multi-blockchain interactions. For blockchain technology to ultimately deliver on its promise, blockchain networks must be able to scale from networks addressing individual business processes to very large scale networks of interconnected decentralized autonomous organizations addressing much larger business problems at the level of entire industries and across industries. In this paper, we envision the inception of Internet of Blockchains (IoB), where homogeneous and heterogeneous decentralized networks communicate to facilitate cross-chain transactions of value, data and state transition. In addition, we also discuss interledger techniques that are essential for enabling industry-scale blockchain networks as well as achieving scalable interconnectivity between disparate, distributed ledgers.