Kenenisa Bekele will lead the London Marathon's elite men's field as four of the five fastest runners in history go head-to-head in April's race.
Ethiopian Bekele, the second-fastest man in history, will be joined on the start line by Kelvin Kiptum, Birhanu Legese and Mosinet Geremew on 23 April.
Returning 2022 winner Amos Kipruto will also face competition from world champion Tamirat Tola of Ethiopia.
"I can't wait to return to London as the champion," said Kenya's Kipruto.
"London always has a really strong field and this year is the same so I know I will face a battle to defend my title, but I'm confident and looking forward to it," the 30-year-old added.
Britain's four-time Olympic track champion Mo Farah will also compete as he prepares to say an "emotional goodbye" at the event.
The London Marathon returns to its pre-pandemic spring slot in 2023 for the first time in three years and will be broadcast live on BBC TV, iPlayer and online.
World record holder Eliud Kipchoge, a four-time winner in London, is absent from the line-up - instead targeting his Boston Marathon debut.
Two-time Berlin Marathon winner Bekele, runner-up in London in 2017, is considered one of the greatest distance runners of all time.
However, the 40-year-old could only finish fifth at his fifth London Marathon last year.
His personal best of two hours one minute 41 seconds is second only to Kipchoge, while Kenyan 23-year-old Kiptum produced the fastest marathon debut in history as he claimed victory in Valencia in December in 2:01:53.
Both Ethiopians Legese (2:02:48) and Geremew (2:02:55) have also run under Kipruto's winning time of 2:04:39 last October.