Pentium 4 Willamette (original P4) debuts the same time as the Athlon 1.2GHz in 2000.
Athlon XP Palomino debuts in late 2001 and brutally smashes P4 Willamette.
Early 2002, P4 Northwood (far more superior than the Willamette) released and eventually regains performance crown from AMD at 2.4GHz. AMD counters with higher-clocked AXPs, but not enough to match with the P4s.
Late 2002, P4 3.06 with hyperthreading released and owns AMD on all fronts.
Early 2003, Northwood with 800MHz FSB and hyperthreading extends the ownage even further. Pentium M Banias released and surprised everyone with it's low clock speeds but yet great performance .
Late 2003, Athlon 64 FX and A64 S754 released. A64 more-or-less equal to the P4 but wins it in gaming apps.
Early 2004, Intel debuts a P4 blunder called Prescott. Runs lot hotter and overall performs slightly worse than Northwood. Intel hands performance crown back to AMD and won't regain it until July 2006.
Early 2004 to Early 2005. A64 gets a new Winchester core and hogher clocks, P4 gets a new socket 775, even higher clocks, even higher heat and moves to DDR2. Dual-core Pentium D Smithfield released, much improved multitasking performance over single cores but due to low clock speeds runs single-threaded stuff slower than single core CPUs. Smithfield is the hottest PC desktop CPU ever released. Pentium-M 90nm Dothan released in Mid 2004 with bigger cache and higher clocks.
Mid 2005. Just as the Pentium-D about to get a foothold, AMD counters with the excellent dual-core A64 X2. P-D relegated to budget dual-core chips from now on. Single-core A64 updated to Venice core with better integrated memory controller, SSE3 support and higher clock ceiling.
Late 2005. P4 die-shrink to 0.065nm Presler core. Runs a lot cooler than the ultra hot Smithfield and overclocks very well.
Early 2006. Intel Core Duo released, can be described as a two 0.065nm Pentium-Ms slapped together. Socket AM2 for A64/A64 X2 released in March, basically an AMD's move to more widely-supported DDR2.
Mid 2006. Intel Core Duo 2 Conroe (C2D) debuts and brutally slays AMD.
That's all.