Mark Handley joined the Computer Science department at UCL as Professor of Networked Systems in 2003, receiving a Royal Society-Wolfson Research Merit Award. From 2003-2010 he led the Networks Research Group, which has a long history dating back to 1973 when UCL became the first site outside the United States to join the ARPAnet, which was the precursor to today's Internet. Prior to joining UCL, Professor Handley was based at the International Computer Science Institute in Berkeley, California, where he co-founded the AT&T Center for Internet Research at ICSI (ACIRI). Professor Handley has been very active in the area of Internet Standards, and has served on the Internet Architecture Board, which oversees much of the Internet standardisation process. He is the author of 33 Internet standards documents (RFCs), including the Session Initiation Protocol (SIP), which is the principal way telephony signalling is performed in Internet-based telephone networks. Recently he has been standardizing multipath extensions to TCP. Professor Handley's research interests include the Internet architecture (how the components fit together to produce a coherent whole), congestion control (how to match the load offered to a network to the changing available capacity of the network), Internet routing (how to satisfy competing network providers' requirements, while ensuring that traffic takes a good path through the network), and defending networks against denial-of-service attacks. He also founded the XORP project to build a complete open-source Internet routing software stack.