River

River Song was an archeologist who met the Doctor for her last time and the first time with the Doctor. Her timeline and the Doctor's continued to intermingle throughout time and space, although never seemingly in the right order. Matty James seemingly met her for the first time recently in the early 51st Century, where he knew her, but she did not know him, whether or not she had met the Doctor yet was still unknown.

Biography
Although the Doctor first met River during a visit to the Library, the two of them had seemingly known each other very well before than. One of their earliest, if not their first, encounter happened when Matty was thrown through time. He was searching fro River specifically knowing she was within the century. Matty ran into a man named Tomy who brought him to River. She did not seem to know who he was, but knowing of her explicitely seemed to give him an in with her. The fact Matty happened to be a time traveler didn't hurt either.

River, Matty, and Tomy broke into the Time Agency and kidnapped a Time Agent using their vortex manipulator to go back in time. They were found by Torchwood almost instantly, and with the help of Martha Jones made their way back to the Doctor. After Omnia restarted the Eye of Harmony, Omnia returned her back to her proper place in the Timeline.

The next time River came in contact with the Doctor is unknown, but during fourh other instances she has met with the trio (or quartet) that now travels with the Tenth Doctor.

River arrived at the wedding of Matty and Hex earlier than either of the grooms. She used her vortex manipulator to jump to the TARDIS with Sam, Matty's sister. During one of the final dances of the wedding, River revealed that she would travel with Matty and Hex soon.

Another encounter with River was during the Paradox Hammer created by the Sontarans. She went to the large shrine to the Time Lords at the Eye of Orion and was captured by the Sontarans. However when Matty and Hex arrived, the three of them quickly found a way to destroy the scheme mostly because Matty was no sort of Paradox. When Matty fully destroyed the machine (and nearly himself in the process), her 'ride' showed up and she left them on the Sontaran ship.

Knowing River would be there to help, the Doctor went and asked River to help before she went to her death at the library. She helped Matty stay alive during his time in the Dalek work camp on Mars. She gave him a variety of protien bars and helped coordinate the events that led to them all escaping. The Doctor then dropped her off right where he found her, mentioning that she would see him soon and to not tell him that she had just saw him.

The first 'official' time the Doctor met her was on her way to the library. It was almost halfway through the Doctor's Tenth Incarnation when he came upon a message on the psychic paper that said come to the Library. It was signed with X's and O's. He came, and quickly figured out it was the Vashta Narada. River seemed to know who he was, but he did not know who she was. It was only when she revealed she knew his true name that he realized they did in fact know each other.

However, this adventure ended in tragedy when River used her mind to download the entirety of the 'saved' people. It killed her, but with an untimely intervention of the Doctor allowed her to survive in the Central Processing Unit of the the Library.